Long story long...
Bought my L85A3 from Extremeairsoft back in Nov/Dec 2022 & within a couple of dozen shots the charging handle fell off (a typical fault apparently), when I went to repair it I noticed a burst thread on one of the dissassembly screws so I summised it was a returned pew then sold to me as new. after emailing extremeairsoft I got zero replies & thought... fuck. determined to fix it I ordered a charging handle set which I 'hoped' would fit (it didn't), earlier this year I ordered a different one (didn't fit), finally emailed Ares direct and ordered the correct one... it came today & WOOHOO, it fits.
For those that need one, this cost £20.10 inc postage from Hong Kong, parts numbers... FC-M3x8 and the UB-478