Factory or cobbled up?

[barnbikes]

 

[kngtmat]

It could be the bike on the top of the pic below of a bike from JC Penney's or something else, it looks close but your sprocket is different with the one on this pic looks like a Murray style sprocket so yours might have been replaced at one time.

http://www.wishbookweb.com/1976_JCPenny ... ge0308.jpg

 

[Jpromo]

Could very well be a Murray Wildcat. JC Penny released a similar bike as well as several other manufacturers. The forks look correct but the rake is off.. the bottom plate, which gave it the lower, longer rake, could have possibly been replaced due to a breakage.