I'd probably ask for a partial refund before leaving negative feedback.
In terms of upgrades, Maple Leaf autobot rubber, Hadron H-arm, Hadron TDC and a tightbore of your choice (I like Maple Leaf or Nineball) are my go-to upgrades for any mk23 build.
@MusicaNo, you need a VSR style barrel. Are you looking to put it into a carbine kit as a DMR? Running a barrel that long into the suppressor could easily take it over 1.14J thanks to joule creep (I know that the clone mk23s that have an inner barrel extension into their suppressors tend to be pocket DMRs)
For sale is Tokyo Marui MK23. I bought this from the original buyer and I've never used it but its still in great condition.
Price includes paypal fees and postage, I can send more pictures/video if required.
Open to offers.
I have other items for sale, happy to do deals if you're buying anything else.