I had the same problem moving on my trailer ,once the 4 bolts where removed yoused plenty of heat and pen oil ,followed by a long bar clamped to the tube yousing a lump hammer to jar it into moving over a couple of days .
I have just collected this trailer , can any one advise the best way to free the hitch so I can move it to the lower position and approx age thanks Graham
Youl find covertions on eBay de ,but with a 4 cylinder engine the rad will have to move ether by extending the front or putting the rad behind the engine.do a image search for diesel Mungas and you will see some of the problems .There is only about 100 km to spair with my 3cylinder yanmman covertion .
the thing to remember with electrics is that a starter systerm that needs 200A at 12v ,would need 400a at 6v for the same power .24v would only need 100A so cable size realy matters .this is also important on lights .
early trailers had the ability to rotate the hitch to above or below the a frame to sute hitch hight on older moters, these seam to very rare these days.
my tester listens after egnoring me when i told him he could not youse brake rolers on my 4x4 kangoo van ,he was stood in front of it when it poped off the rolers on its last mot ,youses a tetla meter now when you mention permanant 4x4.
Hope all goes well with mot, drove my munga to the Muckleburgh colection for there show last weekend ,350 miles round trip only problem jumping out of 3rd gear .
Looking good,you have had far more welding that on mine .Look forward to seeing the finished restoration . Making slow progress on my F91/4 due to the wether.