Cheapest Pneumag Frame

[c0rpse]

I will be getting a classic mag soon, and I want to do the pneumag mod to it. WHat is the cheapest frame I can do this mod with? I am pretty sure I can get a cocker frame for pretty cheap, but will I be able to line the MSV-1 and MPA-3 up in the right places? I am going to put the lpr on the outside, like Big Evil's E frame. Has anyone already done this. If so, PICS PLEASE.


Thanks

[wjr]

I'm doing mine on a benchmark frame that I bought for $30. Benchmarks are good too because they have lots of room inside.