That looks lovely. I really like the classic black and red vibe
TZR looks smart to? Is that yours. Whose is the RD and the blue DT looks nice also!
I wouldn't risk it personally. Just save and get a legit one.
Prox are a good make, better than Mitaka (Not Makita lol they make tools). That Prox was likely to be a forged aluminium one, which is far superior than the cast ones supplied by Mitaka. But I ran Mitaka for years without any issues.
Rings don't just melt, there is definitely something wrong here and I would check this out before throwing a fresh piston and barrel out it.
Often you'll find it'll be down to fueling, lubrication and the like.
I find on forged components that the piston ring end gap is left for the user to spec out, so be sure you do that prior to fitting it all together.
Wow, for that sort of money you can find a complete one for sure