I reckon Matt is right,it looks like a old Wade blower. If it is forget it as they had high pressure lubricated precission brgs and they are probably immpossible to get and would cost a fortune.
The other problem with them is they had either 3 or 4 helical scroll rotors with a sealing strip. If they are worn or the brgs are worn then it is U/S
Go with a more modern type that you can get parts for
_________________
Research is the difference between speculation and investment. Anyone who copys some one else will always be second
www.minisprintgt.com