Not sure about their availability in your neck of the woods, but out here there are the surplus M939 windshield frames on the market. They are longer and wider than the CMP frames, so plenty of meat to cut down and reweld into frames for the CMP or the old deuce. The channel is basically the same. The windshield gasket will work all right too with one corner cut down and crazy glued.
I picked a couple up for $15 each at one of the MVPA conventions and wish I had bought a half dozen more.
Here is an example:
https://www.easternsurplus.net/PartD...eld-Frame-M939
http://www.ebay.com/itm/1-M939-WINDS...-/400770073290