I don't remember if the 750 H1 was a twin or four? On my 650 four the bolt on the back rear of the oil pan can be removed, and a special fitting installed to use for an oil cooler; BUT the fitting also blocks off the oil galley. It does this in order to redirect the oil out the fitting to the cooler. What I'm saying is you just can't remove the bolt and hook up some kind of barb fitting for a hose, you must use the special fitting. And you will also need a second fitting that will attach on the right side of the engine.
You can use the same oil pump you have in there now.
Both fittings are sold by Klasmo (in Europe). I think American Classix (sp?) also sells the fittings. The second fitting I speak of is common, and could be bought at any fitting-hose supply shop.
I also have some drawings somewhere on how to make the oilpan fitting if you feel creative and have a lathe. Let me look around.
Kent
OK, heres a link to the plans.
http://tinyurl.com/38krel
Have you thought about searching salvage yards or ebay for a 750Gpz oil pan? It will swap right in, and probably the cheapest, easiest way to go.