I was told they were Suzuki RM400 forks. I can't find an exact match on the parts catalog. The main difference is these have solid mounted (not rubber mounted) handle bars.
I think they originally had fork gaiters. Those are after market wipers/dust seals. They are 38mm.
The other distinguishing feature is what appears to be cast in number plate mounts (centre top and bottom triples).
I'm thinking of selling them if anyone is interested.
(http://i323.photobucket.com/albums/nn458/mx250syd/OzVMX/P6240294.jpg)
(http://i323.photobucket.com/albums/nn458/mx250syd/OzVMX/P6240296.jpg)
(http://i323.photobucket.com/albums/nn458/mx250syd/OzVMX/P6240295.jpg)