I think a diamond design the best selection for appropriate and approximate matchup with the Camel tank/storage.
Pat's V twin concept so blows all other, commercial, attempts at a true classic period look V twin, mid-drive e-bike out of the water, that he should borrow the nautical "Dreadnaught" as an apt description for his e-bikes. I'm also aware of the quite famous pre WW1 single cylinder English bike of the same name, though a one off race bike, which still
motors during the fantastic Pioneer runs in Great Briton
You may recall I've previously posted my thoughts for faux V engines electric or not, which are similar to your own thoughts on the topic, and a Sportsman Flyer loop frame is so right for this purpose with a classic coffin tank/storage tank which Pat also designed and sells for a quite modest sum. At this point in life, and since I no longer have a complete machine shop at my disposal, buying these components from Pat makes perfect sense. I seem to have parked my creative ego somewhere quite forgotten and misplaced the keys as well.
Your approach with the Camel tank and diamond frame are much more unique and therefore appealing especially on a tri-car build with a gas engine look period correct look..."in the spirit of" a classic!
Build on and have fun Steve.
Rick C.