I was finally able to find an Origo 4100 on eBay for $400, in good condition and complete with cutting board. There are a few of the electric/alcohol versions out there with what looks like the same form factor.
Patrick, without the gimbal frame, I think you will need to custom build something for that stove. Or try to find a gimbal frame from someone parting out another J/30 and then sell that stove and try to get a drop in Cookmate.
It looks like I do need to sort out a gimbal frame. If anyone else has photos of the original gimbal frame that would be very helpful. Of course, if there is a way to get ahold of one that would be even better!
Not sure what age is your boat. Does it sleep 6?
I never answered your question. It is a 1981 and does sleep 6. Looks like the same boat as in your link.