Snapped the bottom bracket in mine a few years back and there not as bad to change as you think with a big hammer some grease and a pair or circling pliers!
As long as you can get a vernier on the old shell and get somebody or company's to machine it down to the correct dimensions for you.
Then it's simply a case of greasing and hammering it in and re-circliping.
As for the axle sticking out thurther on the drive side, yes it should to give clearance for the chain ring and bash guard, the non-drive side should almost be flush up againstl the frame with a 2-3mm clearance with the crank arm on.
I might have some old photos of when I did mine ill try dig out for you.
Be sure to measure the axle length of you old BB correctly after machining a shell for one BB I bought the axle was to short so cranks grinding on bottom bracket shell wasn't very good.
Buying new bolts would be a cheaper alternative, but if you really want to put the graft in of getting rid of the rust then i suggest hammerite rust remover gel, i use it on helicopters all the time works a treat!
its £5 from halfords if you really want to go through the effort.
haha, i had a old saracen mad years ago with dual shitmano disk's on it!
me being 15 decided to tar my back disk, ohh how foolish i was in doing that, just turned to complete horse poop!
and left me needing new pads and rotor for it!
just curious, who are you getting the t-bird off because i know there is a old one floating around the grove somewhere!
and if you need i got a old hope mono trials thats been sitting in my room for 3 years that i can hook you up with for a tenner.
get in touch, good to know theres someone else about in the grove that rides trials