With or without boiler shell. Have a boiler shell in excellent condition,just need a chassis to put it on and a tender.
Try eBay. I did took a look and found 3.
I just looked and only found one and I think $50 for the loco and $15 shipping is just to much for something in that condition
The same chassis, some with a smoke unit and some without, was used on the 29X series, the 28x series, the 32X series, the 35X series and the 31X series.
Basically, any six wheel postwar AF steam engine except for the 0-6-0 PRR switcher will supply the chassis you need.
Some will not have the square for the eccentric crank, but that can be fixed with a jewelers file.
With the 310 having no smoke and reverse in the boiler the only chassis that would truly work would be another 310 or a 350. I have a 350 but plan to restore it. Also would still be short a correct tender. Hopefully what I need will pop up on eBay.
Wouldn’t it just be easier to sell the engine shell you have and put the funds towards a nice matching engine and tender from wherever?
With the 310 having no smoke and reverse in the boiler the only chassis that would truly work would be another 310 or a 350.
Or a smoke in tender 312 or a smoke in tender 322.
I have one that Santa brought me in 1949... My first train!