@German Jäger, our searches always start under the topic of useful information that we find in the General Muzzleloading Forum. There we find three suggested loads for a 14 gauge. Bear in mind that we can always load down and use the information for a 16 gauge being a bit lighter in power than a 14 gauge.
https://www.muzzleloadingforum.com/threads/smoothbore-loads.103462/
Of course, the PDF file only give powder granulation and weight of shot charge and not the stack of wad columns.
I am going to guess that your 14 gauge is cylinder bored with no choke. Measure the bore to be sure that you are ordering the correct diameter of wads and cards. The best suggestion is to order an arch punch to make discs slightly larger than your bore. A 14 bore will be 0.700 inches (17.8 mm). And those cards will be all you need to establish a load column. The load is built at the muzzle. Of course, the powder is loaded first. Then 3 or four of the thin card stock disks are loaded and pushed about 2" (50mm) into the barrel. On top of that is the shot charge and the final over shot card or disc. the entire load stack can then be pushed to the breech with the ramrod and once capped, shot.
In this case, I would suggest a light 16 gauge load to start of 61 grains, volume of course, of 2Fg black powder. Perhaps one over powder card disc then up to 60 grains of corn meal to act as the buffer wad. Now is the time to build the load stack. Use some light grease to wipe on the edge of the over powder card discs. This will keep the fouling soft. Load the 1 ounce shot charge and top it off with the final over shot card. Push the load to the breech, cap and shoot.
Use shot size appropriate to ducks and a smaller shot size for the pheasants.
Your fouling gun with the Damascus or twist steel barrels should be safe as long as there are no signs of delamination. The gun appears to be well constructed and should provide you with a lot of good hunting experience.
At some point in the future, you may want to try using the soaked over shot wad (Skychief Load). Keep the loading simple for now. The simple loads have worked well for many of us.