check this auction out, see what's missing (pretty much everything), enjoy the price:
http://www.ebay.com/itm/VINTAGE-PRESTO-900A4-TUBE-3-CHANNEL-PRE-AMP-FOR-REPAIR-LANGEVIN-ALTEC-COLLINS-/351058863954
Oh yeah, I'd definitely recommend the SquareTrade 2-year protection plan for an additional $239.99.
http://www.ebay.com/itm/VINTAGE-PRESTO-900A4-TUBE-3-CHANNEL-PRE-AMP-FOR-REPAIR-LANGEVIN-ALTEC-COLLINS-/351058863954
Oh yeah, I'd definitely recommend the SquareTrade 2-year protection plan for an additional $239.99.