hehe in that case get some penatrating oil and let that shit for 24-48 hours. they can get really really stuck sometimes. one time i actually had to cut it off.
yeah there are a couple kinds of rigids. they were all made as the cheaper versions of the original bike. sometimes even fully rigid. they all came with 1 speed low HP motors, cheap plastics, skinny spoke rims etc etc. basically for people who were too poor to afford a newport or a maxi. its the same thing in europe too. the maxi N frame is HELLA common over there but thats the frame they all use to race with.
The rigid models i am aware of in the US are the Maxi N which came in a couple colors with a couple different engines, the Swinger full rigid blue in color and the Kromag (freespirit) full rigid in blue.
its possible that there are pinto rigids and murray rigids out there but i have never seen them.