I AM RESPONDING TO YOUR REQUEST FROM MELBOURNE AUSTRALIA. I AM SURE THERE IS A D/C M/CYL FROM AN EARLY MAZDA THAT WILL FIT IN THE CONFINED SPACE WITHOUT A GREAT AMOUNT OF GREIF. IF YOU WANT TO KNOW MORE, LET ME KNOW.
I would be intrested in the Mazda conversion. Are you say it would "bolt in" without mods? Currently the only conversions I have seen (non-Mazda) have all required at least a new bracket to be made. This would be really cool and increase the safety factor by at least the power of two
Depending on your skill level anything can be adapted to work. Vernco website had a how-to for putting a remote reservoir on you original single master cylinder. Other sites will show you how to swap in later CJ dual master cylinders. Or hotrod products like those from Wilwood can be adapted.
The one one thing that does not seem to be available that I would personally like to find, and I imagine there are others who feel the same way, is a dual master cylinder that will bolt on to the existing mountings on an MB/GPW with no modifications.
I put a remote filler on my 42 but I ended up using a Wilwood MC from SummitRacing. It is certainly much easier to fill and perhaps helps keep moisture out of the brake lines...but because it is a "racing" MC it is only single circuit not dual like I would like to set up. Also, I had to make adjustments to bolt it on ( I didn't want to drill any new holes).
Sorry to take so long to reply. The Mazda master cylinder I spoke of is for right hand drive converted jeeps. On the left hand drive I think a master cylinder off a 1979 - 1986 Dodge D50 would probably fit. It has a 7/8 inch bore so the pedal height would not suffer much and obviously mounting brackets would need to be made, but the pipes exit on the correct side for a left hand drive vehicle. The same vehicle in Australia is called a Mitsubishi L200 ute (pickup in your lingo). Hope this is some help.