Definitely not a Pro-flex mate, without doing a little research I couldn't tell you what it is.
Try checking retrobike catalogues.

Under manufacture archives.

http://www.retrobike.co.uk/gallery2/main.php

Definitely not a Pro-flex mate, without doing a little research I couldn't tell you what it is.
Try checking retrobike catalogues.

Under manufacture archives.

http://www.retrobike.co.uk/gallery2/main.php

I believe what I have is a 1995 Nishiki FS variation. It looks like a duplicate of a Mantis Pro Floater. The serial number points me towards a Nishiki.

I got in touch with Richard Cunningham and He said "I designed a similar swingarm just about the time I sold Mantis. They produced a number of bikes with that swingarm, but I only made the prototypes. The Mantis version had a dropout pivot, the Nishiki Alien looked similar, but it was a triangulated swingarm, exactly like the mantis in your pictures. I think it's a Nshiki, or a Nishiki swingarm on a Mantis front triangle. The serial numbers should be stamped on the bottom bracket in small numerals. something like: PF001220...Pro Floater #12 20" frame."

Thanks for pointing me away from Pro-Flex so I didn't go around in circles,
Al

No. It turns out, going by the serial number, that it is a 1995 Nishiki FS Comp.
I'm guessing on the Comp.
Going by the serial number year code, and reading that there were no Nishiki FS-4s after 1994 I'm guessing it is a 1995 Nishiki FS Comp.