Absolutely gorgeous specimen, and probably worth restoration to a buyer that can appreciate.
I almost purchased this bike from the PO over the weekend. It was sold to the current owner 2-days ago and then showed up on CL yesterday at a higher price.
I didn't get a chance to physically inspect the bike, but I suspect the coolant in the oil is due to either a leaking waterpump seal as disclosed or worse case scenario corrosion in the magnesium cases which was common in the Beta Zero. The PO got the bike from the original owner, but gave up on keeping it since he couldn't remove the waterrpump impeller to replace the waterpump seal. I spoke to Mike Komer at the Tryals Shop; Scott Armstrong at Moto Connection; and the original importer: Ron Commo at RCS Racing to get information on the Beta Zero and source the parts:
1. No problem getting the $11 waterpump seal. It's an odd design 10x18x5/8 with a raised edge. Common on many Italian makes.
2. NOS Replacement cases in Aluminium may still be available from Beta in Italy: ~$480 The corrosion prone magnesium cases were replaced in the 1994 Beta Techno.
3, Rear brake caliper and master cylinder rebuild kit. The rear brakes weren't working.
4. A hydraulic clutch conversion use to be available. Maybe the Magura Hymec
conversion kit available from Keith at ADB
5. Early Beta aluminium frames but frame cracks.