Hello,

I bought my 91 907ie almost two years ago and finally got to ride it up the street yesterday, 15 mph. Still needs work, won't idle with the choke off.

But....

After waiting two months for a gas cap o-ring from Ducati, then finding out it is discontinued, I went to KOI auto parts.
They matched one up from a Ford truck.

KOI part number: 35617 FEL-PRO engine coolant thermostat housing seal $2.49.

Or, just get an o-ring from a Ford V-6 244 (4.0L) SOHC Eng.
1997-00

Tighten the nut on the bottom of the cap if not sealing.

Also, if you want a perfect match on the silver parts, I found Dupli-Color engine enamel w/ceramic 1615 aluminum.

The gold fasteners I used Rust-Oleum metallic finish 7710 gold.