Advice on Fixing my 93 Convex Stock

I've read through some older threads on this topic, but haven't seen any recent ones, and I'm not sure how I should proceed.

I have what I think is an HK German 93 series A3 retractable stock.







I really like the look of this stock, much better than the newer styles - especially on my Ghillie built 53 (with sear installed)



versus...the much more compact (and IMO cleaner looking)...



The problem I'm having is the age-old wobble issue. This stock has an inch or more of vertical travel when fully extended and locked. When collapsed it is locked up tight with almost no movement. It has little vertical or lateral movement as I begin to extend it, and only when fully extended does it wobble badly.

It's not the receiver as I've tried it on my 93 and have the same issue. Plus the newer stock is tight all the way around.

Question: Can I get this thing fixed? Who can fix it?