Hi Tim. I to am the proud owner of a K6 and have the same problems as you i.e wind screens I have tried for several months now to get replacment screens but to no avail, just got to keep trying must be some sitting out there somewhere. I would be interested to know how you get on with the leather gaters as could do with some too. My K6 was a generator wagon, Royal Navy prior to that it belonged to the R.A.F. It has a large step on the back, I don't think I will ever get a generator for it so I am going to turn it into a flatbed.
Regards Richard.