I have a V1 as well - great enlarger, however it was quite a rare beast in its day and parts just don't seem to come up - I look all the time. I have 35mm and 6x6, plus a slide carrier, but would quite like a 645, although I can manage with the 6x6. Although they look like a complex plastic moulding, it's really just a clamshell with a locating ring. I am seriously contemplating making one out of sheet plastic. 4x little pins that locate in the circular hole of the stage should suffice for the locating ring, and then it's just a matter of getting the right thickness so the clamp works correctly. I was thinking about magnetic sheet instead of the clip latch (which doesn't work on my 6x6 anyway) A4 sheets of plastic in various thicknesses are easily available on ebay. I haven't made it yet, but I don't think it would be too difficult, particularly as its a glassless carrier. No glass needed on the V1 of course due to the cold light (assuming you are using the dichroic source with light-pipe)