Let's see if
@DogBunny will chime in here. I painted some early XS-1 ears for him that he's putting on 35mm forks. So, according to him, it's doable. Maybe he'll give some details?
Yes, it is very doable by employing a mash-up of 34 and 35mm parts. This is the mock-up I did a long time ago, and that has been sitting since, so excuse the dust. I don't exactly remember how I did it, but this should get you close.
Before I get into the details, let me say that you should not be bothered by the fact that my fork tubes do not poke all the way up through the top triple in these pics. That's just for expediency in the current state. I had been doing a lot of dis- and re-assembling, with more to come. The tubes WILL poke all the way up when the time comes.
To the best of my recollection, without disassembling my mock-up, here's what I came up with, starting at the red arrow, and working my way down.
The red arrow is the thick washer 1T3-23146-50-00 from a 35mm fork that normally sits directly atop a 35mm lower triple.
Next. I think, is the lower 34mm packing 256-23163-60-00. I have moved it from below the fork ear to above the fork ear, and I have flipped it, so that it slips into the thick red arrow washer, I think.
Next is the lower guide, 256-23116-61-00, which is normally below the fork ear, but I have moved it to above the fork ear.
Next is the fork ear.
Next is the upper guide, 168-23115-00-00, which is normally above the fork ear, but I have moved it to below the fork ear.
Finally, I think, is one of the thick gaskets from a 35mm fork.
For clarity, I think this is the thick 35mm gasket I used (but I did NOT use the associated chrome guide). Maybe I trimmed it????. Don't think so, but who knows, it was a long time ago. Also, to the right, that's the thick red arrow 35mm washer.
If you're wondering why I reversed the positions of the top and lower guides, and why I flipped the 34mm packing, and why I used some 35mm fork parts, the answer is because this is the only way I could get it to work. Getting smaller diameter 34mm rubber parts to slide on a larger diameter 35mm fork took some doing, especially when also trying to get them to fit into the guides. It required lubing with Sil-Glyde and patience.