Find out exactly what "freshened" means, how much bore, bearing, size, etc. Might spend the $ or get a Guarantee from them about magnafluxing to assure it's not cracked. Or the extra mile would be to sonic check too. Check on Mummerts site for all the numbers and you can exactly id it. mite be worth it depending on the machine work that "may" have been done.
Good machine work isn't cheap.
just my HO, but the 312 to me is no longer any big deal because of what can be done with the 292 and a 312 OR NOT crank.
Let us know what you find out. Sounds interesting?
A L A N F R A K E S ~ Tulsa, OK