Rudolph Optics - gone bust? Are they like all the others?

Does anyone know what's up with Rudolph Optics? They had a NZ site, but that's down. While it was up a few months ago, I couldn't get through to support. Now I can't even get through to anyone at their main sites (ZA, USA). Tried email & Instagram.

Have they gone bust?

I have their VX1 2.5-15 scope. It actually works great. The only reason I've been trying to get in contact is because I lost the threaded battery cap somewhere in the hills.

The scope I have looks I lot like any other budget scopes (Arken, etc.). If optics are like many other industries, Rudolph is just a brand reselling off-the-shelf mass-produced scopes. If that's the case, I may be able to just got a cap from another brand.

Does anyone know if there is a larger company they rebrand from who I could get parts from? Or if they have gone totally bust (or are just super shit at support)?