So what's the closest todays tobacco they would have sold at the Rendezvous?
Well luckily, tobacco hasn't undergone too much of a tech revolution in the finished product, but improvements have been more in control of consistency and improvement in storage to prevent loss of the product, SO if you look around a bit, you will find stuff that is likely quite close to what folks actually had even as far back as the AWI.
Here's a basic answer..., simply because tobacco makers have their own specific steps to producing each version, and this answer leaves out the nitty gritty stuff that varies from company to company. They had leaf, rope or twist tobacco, flake tobacco, and plug.
Short Answer: You want flake or rope/twist for pipe smoking, that uses American, Virginia and/or Kentucky tobacco... no tobacco grown outside of the United States in the mix...., for rondezvous.
Detailed Answer (and a lot of this is my opinion) :
So leaf tobacco was simply cured but not further processed tobacco. This is likely what the tobacco farmer and his neighbors smoked. After the tobacco was air cured and aged a bit in the barn, it could be crumbled and used in a pipe. Leaf could be cut lengthwise, into ribbon tobacco which was then made into cigars. (this can be tough to find as usually it source is the tobacco farm, itself)
Rope or twist was just that, cured tobacco that was twisted into a rope shape and wound around a spindle on a small platform. It further aged as such and was also easy to ship. Shipping the stuff to England or Europe was how the "flavored' varieties such as rum, whiskey, cherry [brandy] flavored tobacco came about. The tobacco would be infused with the liquor to ward off insects, and would dry during the voyage and perhaps further storage when it reached its destination. The smoker would buy a portion of the "rope" cut off. It might be in discs, it might be a section that the smoker had to cut into discs and then rub to make it resemble what we today call "shag" to smoke it. In a shop in a town it might be reduced already from the rope into a smokable condition.
Flake was the same idea as rope but it was leaves of tobacco stacked and compressed and often resembled a block. Slices off the sides would be sold as Flake tobacco. Like rope, liquor could be added to the leaves prior to pressing as a form of preservative.
Both twist/rope and flake travelled well back in the day. Modern pipe tobacco is "shag" and it is done that way for two reasons. First, it's ready to pack into the pipe and to smoke. Saves time for the smoker. Second, it is super easy for a tobacconist to blend many different types of shag to give the smoker just what the smoker likes, and fitting the style of pipe and smoking style. (Shag also became popular when the cigarette became the rage, as it does very well when rolling-your-own as was the practice. From what I've read it really wasn't around until the cigarette was around) Shag doesn't store or ship well compared to twist/rope or flake, without some modern tech.
Some fellows prefer a shorter stemmed pipe, some a longer stem, some like a various amounts of bend in the stem, and some don't. Some smokers smoke the tobacco rather fast compared to others. So the blend of the shag tobacco not only is of flavor, but of burning quality and the smoker's perception of the "heat" they experience.
So again look for a flake, or a "twist/rope" that uses American grown tobacco. BUT beware as you will find twist/rope that is made from chewing tobacco..., not for smoking in my opinion. Flake are slices of a "plug" but don't confuse that with plug for chewing, again as that is not for smoking.
As for flavorings well those based on liquor would be what was around back then.
To save some cash, you can look for "ready-rubbed" versions of flake. This is proper flake tobacco, but I suspect that the sellers take the perfectly good end bits that the purists would reject because of how they look, and these ends are then "rubbed" to be ready for smoking as soon as the buyer opens the package. Smokes and tastes exactly the same as the more expensive and pretty leaves of flake tobacco. Take advantage of that if you wish.
LD