Nice looking bike! I see it has the "track" crown like on the one in post #37 by Dylansbob . Super cool sand-cast "faux two-plate" design similar to the Fischer popular with Italians like Masi, but I think yours is British-made, possible Davis. His crown has indents in the blades like those normally seen on chainstays, does yours also? That would allow quite fat tires, but it seems unnecessary for anything like a normal road tire. Only other forks I can remember with indents in the blades like that was on some old Schwinns like a '50s World, and a Paramount tandem. I might have to try that sometime for a 650b conversion... <gears turning in my brain>

Your geometry looks to be on the steep side — do you know the angles?
Is the TT sloped, higher in front? Could be camera angle. If it is sloped, and if you don't happen to prefer it that way, you could add rake to the fork, lowering it. Plenty of room in the brake slots to raise the pads. Of course that would change the handling, but for the better in my book. Controversial subject, I know. Especially with the added complication of "undoing the original builder's vision" or whatever, plus the possibility that the chrome could crack, so file this one under "crazy ideas". I'm just spitballin' here.

Have you tried a longer chain? I think it might shift better, with the cage rotated clockwise the upper pulley would be closer to the freewheel. I know, with an NR, you sometimes have to play with the chain length to get it to shift to a decently-low gear for old guys, like 28t or more. Is that what you have one there? 26 maybe? Anyway, apologies if you're already at the optimum length for your gears.

Now go get some dirt on that bike, it's too clean!

Mark B