I start with hot soap and water; then I go PAINT THINNER (NOT LAQUER THINNER)
I have restored many old stocks, for myself, and gun owners;
If its not oil base paint, then its latex;
you will know right away if its oil base, cause non of the above will cut it;
if it's laquer (which most older guns are), then you have to strip it down, and start over;
I will make a statement here;
For antique or older items, DON"T DO ANYTHING TO IT!!
you will degrade the value and price if you mess with it!!!!!