ALtec 612C question

Hi,
I may be able to get a hold of up to four :eek: Altec 612C units in the near future. I have a few questions :D
I understand that the driver is probably a 604 variant (these particular models date, I think, from the mid to late 70s), but could the drivers in fact be something else?
If it is a 604, does anyone have any ideas which type it might be, and what I should look out for in terms of condition / relative quality?
If I did get either two or four, I think it would be interesting to put them in a more "doemstic friendly" cab - not necessarily smaller, but a more acceptable shape - probably more vertical. Finally, is their any meaning in putting two 604s together in a single cab?

TIA for any input

Joel / Tokyo