Best Integrated All-tube Amp?

I own an Almarro 318, and use it in my video system driving a pair of Diatone single driver loudspeakers in bass reflex cabinets, all sourced from EIFL in Japan.
The amp is truly musical and full range, and very much underrated, using the same output tubes as the Lamm mono amps in Class A single ended mode. When I tried it listening to CD's in this configuration, the resulting detail and musically involving resolution were quite a shock.
I would happily use it in my main rig to drive my Ocellia Tilias, single Phy-Hp driver crossoverless speakers if my custom made 3D Audio 300B ever died on me - at least until I got it fixed! I don't foresee this happening, but I did use it until my 300B arrived, and its performance was right up there with the 47 Labs Gaincard it replaced. At it's current price its a steal.
I listen to everything from Ella to Marilyn Manson.

The Bel Canto SETi40 fills nearly all of your criteria. Uses 2 845 tubes and provides 40 WPC Pure Class A, zero negative feedback and and has a remote. Mark, at Bel Canto provides exceptional Customer Sevice and Bel Canto are an established firm.
Not cheap, but used, it is affordable. Read the reviews on Google.

Why not hybrids ??

I am not aware of an integrated amp that meets your requirements (single-ended, triode, 300B-based, class-A, no negative feedback, low distorsion, point-to-point wiring, good bass, and a well-known brand), especially one that is "affordable", whatever you mean by that.

The VAC Avatar is about the only thing that comes close, and I believe it is $3k-$4k used. The VAC Renaissance 70/70 Mk. III amp (not integrated) meets all of those requirements other than being single-ended (it is push-pull), but costs $5k-$6k used and you would need a preamp. The VAC amps do come close to the single-ended sound and avoid the significant disadvantages. Singer in Union Square carries VAC -- ask for Dave Lalin.

I agree with the others - you have way too many requirements. You are making yourself overlook many good options (like the Mc2275). I second the Jolida 302b which is cheap and comes surprisingly close to fantastic sound quality. I have one in my audio room now and it was a shock to me. At its price, you could try it at least.

Don't get hung up on circuit design details (I am an electrical engineer). There is more magic involved that you think and basing your decision on your criteria is doing you a disfavor. Trust your ears instead. If you love the Mc, go with it. Good luck! Arthur