Now that the prototype is finished and I have fell in love with how it rides I am going to remake it into this.
Same geo but with nicer stylings (in my opinion), more tyre clearance, 44mm headtube and space for a front mech. Just need to save up to buy the ring roller.
Good luck with the curved tope tube. Try reading up about it, it's a big subject bending tubes. You can get professionals to do it, but it's very expensive. I spoke to a chap at Bespoked Bristol who has a single seat tube custon bent. He said that one tube cost more than all the others put together!
How about two smaller diameter tubes, like an Ancillotti. Small diameter tubes are easy to bend.
Yeah I know its a pain in the arse, haha. But I have been looking into the manual ring rollers and have found some reasonably priced. Currently in talks with a guy who sells them thats adjustable up to 40mm. Just need to find out if it works with round tube. it will slightly flatten the tube I expect.