guaranteed 33 box? i wish!
i've yet to swap my own box out, which the 2nd gear synchro is pretty tired on, by just 40k,
yet my sprint has done 97k without being touched, and sweet as a nut!
i bought another 33 box from liam, which i'm 200% confident is exactly the fab condition it is claimed to be, partiuclarly having removed the sump and inspecting the box, it looks virtually all new!
but it could so easily be very different with these things, and clearly mileage is no indicator of likely condition.
not much i the way of constructive advice i suppose, sorry, but maybe the better way IS to have your own stuff rebuilt with some sort of gurantee with it.
you could be buying and trying boxes all year before finding one youre happy with!
many of us could certainly vouch for BLS work, but whichever way you go, good luck,
ps - have you tried charlie who is selling all the sud stuff, i think he had a handful of boxes???