The early colorful Coltwood stocks are the most valuable and the least likely to shrink. With apologies to CJS57, if you want maximum return, put them on eBay with good pictures, to include installation (without the screws in place) on a Model O to confirm that they are not shrunken. I suspect they will bring around $100 on eBay. Most listings in the classifieds here would bring a LOT more on one of the auction sites. If you decide to list them on eBay, give us a heads up so interested forum members can bid on them.
I've had good results selling on eBay now that they lifted their parts restrictions. Desirable parts like those described will fetch at least a fair price maybe more. I just sold some WWII GI M1911A1 magazines that had the were marked and got good results.