Okay let's start with the engine...
serial number stamped to the shroud?
or is your serial number on a sticker/decal ?
the latter one would date it Feb 17th. (48th day) of 199
5
stamped numbers are more difficult since it's either 1975 or 1985
(you can maybe tell by the appeal of the engine)
but since the 593-00 mini bike was introduced in 1994 for all I know that's rather unlikely
Now the bad news.. I don't know if the mfg date is coded into the Manco serial number at all.
if it isn't all we can say without a list of serial numbers is
that it's been made between 1994 and 2000 (when the 593B was introduced)
If that's the original engine it came with then we can somewhat
safely assume it's been made in 1995 (maybe march/april 'ish.. june perhaps?? I doubt it'd been much later)
WAIT hs50??... the original enigne was a HS35 not?
'sid