Hi and welcome. The numbers you gave aren't any good for dating it, there just aren't any records to go by for the Asian machines. If it was made in Japan, my guess is it's from the 1970s. If it's from Taiwan, my guess is late70s to mid/late 80s. A damp cloth to wipe the surface dirt off may be all you need. I use TR3 Resin glaze as a finish on my machines, other people use different things like Dawn dish soap, Go-Jo hand cleaner, what ever works for you. Just test it before you go over the whole machine.
Cari