273 dilemma

I’m looking for opinions on how to proceed with a problem I have with the 273 commando engine that is matching numbers in my 67 formula S fastback barracuda that I bought recently.

The car is an unrestored survivor, and the car has been stored inside for 30 years by the original owner whom I bought it off.
I pulled the engine to inspect it since it will need a new gasket set and seals at a bare minimum and unfortunately I found that at some point the torque converter must have been ballooning and pushed the crank forward which wore most of the side of the thrust bearing off and unfortunately are 40 thou into the crank.
I took the crank to my trusted machinist who said it is unusable as is, and the only place he knows welding up cranks like that is a marine engine specialty place in California that costs a fortune.
I’m really bummed as it is a beautiful forged crank, but so be it.
So my big dilemma is what to do now. I’m trying to find another forged 273 crank but am having zero luck as I would love to save the matching numbers engine. Another guy suggested you could easily throw in a 318 cast crank but I have to think that because this is a commando engine that has tee HP parts that that idea might be a big can of worms in regards to throw length, balancing etc.
And the 3rd option as I see it would be to find a decent running 340 and drop it in since it was a period correct option and drive the car.

I’d love to hear opinions on all of those options by any of you here that have done it or heard of people’s options in a similar situation.

Cheers!