A1,
As mentioned previously, you want ALL castor fuel. There should be some CL flyers in Louisville who can point you in the direction of a hobby shop that has CL stuff.
What engines do you intend to use?
There are after market mufflers available for some engines. You may have to look for a Tatone Peace Pipe or Calumet. These are no longer produced but can be had from swap meets and from other modelers.
Depending on which .15's you have, the 52' x .012 would be fine. You may have to adjust length to suit. The next smaller standard length is 42' which is a bit short for a .15.
Make sure you check the planes over thoroughly before flying them. You may find that warps have krept in, covering is brittle, glue joints have become weak. Especially check the elevator hinges for strength.
Those are two fine designs you mention and are well worth the effort to restore.

Good luck,
George