Not a PXN10 but even better, that one is a PY10! The red 531 label and chrome stay ends make it so. Good luck. I hope it works out for you, it’s a special bike. It’s a few years older than mine. With a non-pantographed fork crown and the decal scheme it exhibits, I’d say 1980-81. Here’s my 1983 unrefurbished and as found.
Here is a shot of the later 1983 fork crown to illustrate the difference.
