You can't make stereo from mono. The very word - 'stereo' - means two.

The same as you can't make cream from cow shit!

Forget it - appreciate the sound you have and devote your thoughts to polishing the playfield, swapping out worn rubbers etc

 can't make cream from cow shit Thats great Mike.. i'll have to remember that saying!!

Couldv'e used that one a few months ago when a mate of mine had this bizarre idea of putting a crossover and tweeter into his Zac Time machine pin to "make the speech sound better or clearer"  took me ages to convince him it wouldn't help. told him it'd be the same result as putting an old 8 track cartridge player thru hi fi speakers and expecting it to sound good