Unable to craft any armor polishing kits. Only recipes for the ones cast from molten metal in the smeltery show up in JEI. To be able to cast them, you need to create a cast with an armor polishing kit crafted from the part table, but these recipes are not available. It's possible that these recipes are unlocked later on (haven't completed the modpack yet), however, if they are, they are unlocked too late, as I'm sitting in Atum in full construct's armory gear without any polishing kits right now.

edit: I checked again and realized that not only the polishing kit was missing from the stencil table, but all of the construct's armory components. Since I crafted the others earlier, I tried to mine and place the table again. Then they became available again - including the polishing kit!