Looking for a tailcap

I ordered some cheap zoomies off eBay to mod into scope mounted lights for varmint/hog hunting. The ones I picked up are great on the head and pill side of things. Everything screws together with indentations for pliers, perfect for modding candidate.

The tail cap on the other hand sucks. Not only are there no indentations, the switch is (barely) pressed in, not threaded in. I've already had one switch push out easily, and that's not going to work. So I am looking for a replacement tail cap that the switch threads into, not only will it hold up better it will give the option of upgrading the switch if needed.

I measured the outside diameter of the body/cap at 28.5mm. The OD of threads on body are 24.75 mm, and ID of threads on cap at 24.4mm.

I also have another similar eBay zoomie with compatible threads. My dad has an Elusive Wildlife XLR100 (he didn't know better) with compatible threads. This suggests to me that it is a common thread size for flashlights. I've actually used the remote switch from the XLR100 on these zoomies so I know it fits, but they think too much of them. I would like to get 4 so buying lights to cannibalize isn't really feasible. I've seen tail caps on all the sights, problem is everyone lists compatibility with lights, not dimensions. I don't know what other lights might be compatible with this one. Any help is appreciated.

This one at Manafont is the only one I've found with dimension that suggest compatibility, but they are not taking orders. Unfortunately the models list doesn't help.

Sorry if this is posted in the wrong spot.