For sale: One used Unicolor Uniroller drum roller model 352. Yes, this model auto reverses. Good condition $40 plus shipping from 47150.
To sell separately: one matching Unicolor 8x10 drum, good condition, includes one extra gasket, $20 plus shipping. This drum has the slots/ribs at 5" intervals inside, so that one can insert 4x5 or 5x7 sheets, as well as 8x10's.
Doesn't need spacers! Has integrated raised channels for the film to slide into (look closely at photo)... I used to process both 4x5 and 5x7 film in these. I don't remember how many 4x5's will go at once, but probably two, just like with 5x7's.