I dug a few Ruby Red releases out to check the etchings and heres the results:
Evolution Bridge - Simplicity
Raging Rockers - Swing Thing
Raging Rockers - Kounter Act
So, yeh, its got the hallmarks of a Ruby Red release, although, as I'm sure you've checked the LTD13 release is missing from the RR catalogue on discogs. https://www.discogs.com/label/12570-...ar&sort_order=
The MT etching is the pressing company Musictech. Perhaps that's a route which might turn up something around that time?? https://www.discogs.com/label/380740-Musitech
Had a listen, but never heard either - interesting one. Hope some of this helps and you get it ID'd at some point.