Something like this? I was guessing it was a crosman, couldn't find any pics but the crosman site had this owners manual
http://www.crosman.com/pdf/manuals/crosman/AIR17/CAIR17-OM.pdf
The A.I.R. 17
http://www.crosman.com/pdf/manuals/crosman/AIR17/CAIR17-OM.pdf
The A.I.R. 17