In any mesa cab they will all be UK V30s unless someone has changed them from stock form, but there is still the whole rabbit-hole of which years sound best.
Those older rectifier cabs have a tighter/thicker weave to the grill-cloth, meaning you can't really see the speakers even enough to know if the dust-caps are large or small.
Also, the older standard rectifier 412 slants not only have the straight-cab shell with a slanted baffle, but they also have silver piping around the grill-cloth. Those were the "golden years" cabs that are more sought-after. Specifically the serial#s that fall in the 00-03 range iirc.
I snagged a local great condition 2000 straight-slant for $400 back in 2013, but the inflation since then is just craziness.
As with most things it is a matter of opinion.
IMO they all sound great, and since speakers have a fair degree of variance from one to another you can either get a good 412, or get a great 412.
Not a bad gamble.