Fitting oil tank ... without scratching the surrounding paintwork

i'm all ears here - i'll be into the same thing shortly. one question, you said, "I READ the first component..." -- what are you reading? some sort of restoration book or assembly manual, or what? i'm assuming you're referring to scratching the frame's surrounding paintwork.

not to highjack your thread, but one area I need to address is the oil tank. my aft rubber mount is sheared in half. figure on removing the tanks assembly, inspect all the lines and hoses, and a little clean up and paint up. my battery tray also needs some cosmetic attention.

anyway, good luck....

You are worried about the wrong issue, the later oil tank goes in fine if care is taken but what have you done about the bottom threaded insert. If you use it by inserting the bolt eventually the tank cracks around the insert from it taking all the weight of the tank and oil leaks out the tank. I had 2 tanks go that way, so for the third I ground the insert flat, had a plate welded over the top and added a rubber pad for it to sit on and upgraded the 2 weak top rubber mounts. This has finally sorted the issue.

It's a tight squeeze. I just did this, and the only way i could get it in, was to install the banjo bolt after it was placed in the frame/battery box area.

And yes, @kommando is correct, you need to think about fixing this issue. I went with the upgraded oil tank mod that Matt at CNW does, thinking it could fail at some point and I should take care of it sooner rather than later, and was surprised to find that my rear mounting tab was cracked when I removed the tank. It was hard to tell it was cracked, and it was really only a matter of time before the tank failed.

Now I've one more thing to check in to since I'm going to replace the rear bobbit.

First you fit the horn, then the frame and then work your way out.

Ham can is scratchy

Put several layers of painters tape on the frame tubes. Protects the paint from nicks and scratches. And yes, put the horn in first.