Hi Pintail, welcome to ALR. I admire your desire to do good work, especially given the adversity you face. Hang in there... I wish you well.
..... Will these be PC for a Lancaster?
I believe to do appropriate carving on a long rifle you will need to use traditional hand tools, gouges, chisels, etc. If you use a power tool, it's going to look like you used a power tool. Also, the appropriate carving will have at least some raised (relief) carving... tough to do with a dremel.
The picture DrTim posted is a fine example, but your first carved rifle doesn't have to be that fancy. A simpler design, executed well will look great on your rifle. As suggested earlier, look at the reference books for ideas. The cost can be an issue, so check them out from the public library and/or the Inter-Library Loan program first, then decide which to buy.
I can't draw worth a hoot, so I trace, copy, etc. You can pull elements from several pieces to create a unique design. The clear plastic french curves I found at the hobby shop help me get nice smooth lines.
You don't need to buy a huge set of carving tools just to try it out. Search the web for woodworking tool suppliers and look for hand carving tools called "Power Grip". They are Japanese and sharper than @!*%?&. Get the small gouges and V tools. They cost $7 to $9 each and will get you started. I have found some on sale as low as $4.
Magnification could help. I have one of those lamps with the articulating arms and a built in magnifying lens. It can be a pain to constantly position it, but I won't carve without it.
Good luck and keep showing your work. I know from experience, the guys here are happy to teach those with a desire to learn.
-Ron