Help ID this SBC 6-71 blower manifold

A friend bought this with a 6-71 over 20yrs ago and needs to know what make it is before he puts it on his 57 Chevy. It suits a SBC but that's all he knows. Water crossovers at rear with no provisions for a radiator outlet or thermostat housing on front, only 2 x outlets in front. Blow-off valves area are front and rear unlike my old Edelbrock manifold where they are on the sides. As it is polished, all castings marks and logos are no longer there. Any ideas? The mounting bosses have been rewelded at some stage in its life. The blow-off springs are screwed up so tight that if the motor sneezed who knows what might have happened

 

BTTT, surely someone must recognise the manufacturer?

 

Never seen one like it..

 

Are there any numbers on it anywhere?

 

The pop off valve looks like the one on a Cragar blower manifold my brother had for an early hemi, otherwise ????

 

No numbers, stampings, castings, completely smooth. . Nothing on underside either. Manifold appears original and not to have been port matched or machined; both front and rear surfaces where it seals against block have been lightly pin punched by hand, most likely to assist in gaskets seating and not slipping.

 

Yep, it's old. This catalog page is from 1961