Question about kill rings

Don't paint them. Use white decal striping.
Gip Winecoff

Kill rings are place in the barrel starting just after the muzzel brake. yes you can use them on a mid-production, you can use them on any German AFV. One or two rings is always nice to see. I usually paint, then a slight wash to make them look not so new.

As you have the Tigers In Combat book, you'll see that they were used occasionally and not universally. I would recommend that you choose a specific Tiger in the photo documentation and try to replicate its specific markings. Otherwise, try to stick to known patterns and examples (numbering, unit insignia, etc.)

I saw one pic that showed ring of different widths, widest at the muzzle brake. I assume these wider ring signified a set number of kills (10, 25, 50, 100 etc.) The narrowest rings were spaced widly down the barrel with something written between them and they stopped befor reaching the barrel recoil sleeve.

I have seen images with WIDE white bands indicating multiple kills (ie. 10) and thin bands for single kills.
I once stood next to a P47 that had swastikas for kill marks next to a row of target types (trains, tanks, buildings, aircraft) and there were kill marks for each type of target.

good luck, have fun