Thanks mate. I wasn't concerned about the leather straps as I hadn't thought about to be honest! But given a lot of welding gloves etc are leather I'm going to assume they should be OK. They're pretty thick straps, ex-military, so I'm guessing they should be pretty hardy. Will have to keep and eye on that one, could be slightly embarrassing fanging down the highway with the oil tank dragging behind me...
There will be another mounting point (steel) to stop it flopping about so if one of the straps does fail it should still be OK to get me home. I was also considering hiding steel straps under the leather so it's a bit more sturdy but still has the look of the leather. Still fiddling with the mounting really.
Front fender I'll be making up as I go along. Tossing up whether to try and shape my own out of copper sheet, or try to find a blank or old one from another bike that I can modify and copper-plate.
Yep, internal cables for the brake and clutch, though again, I haven't exactly thought that one entirely through, but shouldn't present any major issues that I can think of.