They were originally available with synthetic stocks, hardwood and Walnut. I have converted quite a few SF blind mags to the old style DBM you are asking about, but have never gone from wood to synthetic. I see no reason why it can't be done, though. The bottom metal is not used in the synthetic models, they just cut a hole in the bottom of the stock and slipped the mag through it. Was kind of crude looking, but it worked. Mine have all been RH, of course, so I can't offer you a stock or I would.

Don't know if that helps any, but at least you know they were once available. Might check Numrich.