Originally Posted by ThayerRags

The 26603 feed works with the 26605T (Teflon coated) or the 26606 (small hole) plates too, to give you couple more numbers to look for.
The Singer 31-15 Chain-off feet have a cutting edge on the back side of the foot, and I believe that it’s used to continue sewing after the material has exited the foot for a distance, at which point the threads can be cut by pulling the item toward the operator. I’m not sure what the “LG” means. (Maybe “Large hole, Graduated?)
The feed that matches plate 147150 is 149057, and the matching foot is S536.
Plate 52032 (old number 147154) uses feed 52031 or 52031R (rubberized). You have your choice of several standard hinged feet, selected by width, 24983 (7/16” regular), 19336 (1/2” wide), or 127233 (5/8” extra wide). Put a “T” behind any of those numbers for a Teflon-coated foot. The original hard feet 12141 (regular) and 12144 (even toe) should work on the same plate and feed, but I’m not sure.
I don’t know what the number is for a roller foot that matches plate 12482 and feed 12481 (old number 149481). Maybe it's an aftermarket foot. I use the small roller foot (7/8”) 12264 with plate 5709 and feed 5708 on my Singer 31-15 treadle.
CD in Oklahoma