Kubota SVL 75 Missing Gas Cap

Just got my SVL 75. When I bought it, it didn't have a gas cap. Dealer replaced for me when I took delivery.
It was a locking cap and had an extra key. He told me it was $80 to replace!
I filled it with fuel and went at it. After just 2 hours I noticed....GAS CAP MISSING!
I searched and searched...couldn't find it. Went on line to buy another....$110!!
It has a BIG opening on this...I need to measure exactly, but I'd say atleast 3"....so...

Does anyone know ...
1. Part number of a...

Kubota SVL 75 Missing Gas Cap

Kubota SVL 75 Missing Gas Cap