Let me just say that I'm sorry to hear that about the Swedish, like many lands in Northern and Central Europe, you had such a great hunting and shooting sport culture for so long
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To check-over a revolver for serviceability:
If you have access to a caliper (it doesn't have to be a terribly expensive one, and they're useful for other things as well), that can be used to ensure that there are no bulges in the cylinder or the barrel, I would check that first (make sure the cylinder's round, and the barrel is consistent down it's length, that is, no abnormal bulges or divots on it that would indicate unserviceability). Most likely it's fine, but never hurts to check. Pay attention also to the chamber mouths, and ensure that there aren't any big nicks or dents there that would compromise it (and make the shot go wild from that chamber)
Then, remove the cylinder from the frame, remove the cones (nipples) and place a piece of white paper behind the cylinder and look in the chamber mouths, shine a bright flashlight on the paper. In this, we are trying to see if there is anything abnormal going on in the chambers that would indicate unserviceability. the insides should be smooth, or only have minor rust and very little pitting. Look at the cones, paying special attention to the vent, looking for excessive wear from gas cutting that would indicate replacement cones are warranted, they last a long time, but inevitably are consumables. (make sure your caps fit the cones tightly, so you don't risk a chain fire from one of them falling off during firing)
Next, do the same to the barrel; place a white paper in the frame and shine a bright light on it, then look down the muzzle and look at the bore, it should be shiny, or at most, lightly frosted with rust with only minor pitting, there should be no gouges or cracks in the rifling. Pay attention to the forcing cone at the back of the barrel, to ensure that the wear is even. Uneven wear would indicate the revolver is getting out of time (almost always fixable, but is unsafe until it is fixed, as you are literally hitting the gun with the bullet each time if there's uneven wear).
If all of that looks good, place the cones back in the cylinder, and the cylinder back in the frame and bring the revolver to full cock, does the cylinder rotate excessively? it shouldn't move hardly at all, and if it does, we will either have to fill in the cylinder-stop window on the frame a bit, or get/make an oversized one to fit it tightly (it's not a complicated part), this will prevent further peening of the window and the revolver from getting out of time in the future. Decock the gun, and without releasing the trigger, does the cylinder move excessively forward and back on the axis pin, it shouldn't move very much at all. If it does, we will need to shim it with very thin washers to help keep the gun in time and eliminate future damage from the cylinder slamming around upon firing.
Ensure that there isn't any excessively rough points during the cycling of the gun, which would indicate damage to the internals (from rust usually). It wouldn't hurt to take a moment and carefully disassemble the internals and clean them (take pictures as you go with your phone so you can see how everything goes together, place parts in cups or bowls to ensure they don't get lost), and possibly lightly polish them with a soft rag and very fine buffing compound (particularly if there is a smidge of rust on them (turtle wax makes a paste for aluminum car rims, and I use it quite a lot for stuff like that). having smooth parts inside will limit the stresses on the parts during the cycling of the action, and that will help keep the gun from getting out of time/breaking things in the future. If you do use buffing compound, ensure that the part is 100% free of it before reassembly, as it will continue to abrade the metal if it's left on, and the action is cycled (a bit of acetone/brake cleaner will do it). In any case, oil the internals to protect them and minimize friction. Make sure not to damage the screw heads, so try to use a properly fitting hollow-ground screwdriver bit every time.
It is incredibly rare that these guns cannot be made 100% shootable again, if they've gotten a bit excessively worn; it's a matter of time and money, and where originals are all that are available to you, it's worth the time and money, I'd say. As far as loading, I would shoot a round ball and roughly 25gr of fine powder (4F) for target shooting/general practice, to limit recoil for you, and to take it easy on the gun. But I would always start/end the range session with the conical bullet and a roughly 25gr charge of fine powder (4F), as that is what you will be using for personal defense. With 215gr bullets, and 25gr of fine powder, you would have something that is the equal to the later .45 Schofield (S&W were literally trying to make a faster loading version of the 1858 Remington and 1860 Colt when they came out with it, and the US Army liked it), and that was/is still a good loading for personal defense.
So long as you are confident that the firearm will work, and you are confident in your shooting from practicing, you need not be too concerned about it's capability. Living things do not do too well with holes in their chest, and god-forbid you do end up having to shoot someone, a 215gr .45 bullet at roughly 820 fps will cause a grievous, potentially mortal wound to your would-be assailant (let alone all six). These guns were made to do this kind of work, and they can be made to function in their intended capacity again, as needed.
. but from his description of that revolver, he has an almost pristine condition Remington, which would be a prized possession in my opinion 
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