Ok so I put wheel back on to double check clearances. Seems awfully tight fit to me but I'm not really sure what is considered roomy and tight when it comes to this stuff. There is plenty of space between tire and chainstay bridge, like 5/8" or 1.5cm. Between the sidewall of the tire and chainstay is a hair under 1/4" on one side, and about a 1/4" on the other side, 6-7mm. My wheel dish may be just slightly off center.

If it's no big deal I think I'll mount the fenders so they end just above the chainstay bridge with enough gap to prevent scratches, would definitely be easiest way to go and most clearance. Of course with the fenders spaced up a little the fender doesn't have to squeeze between tire and chainstay as it sits more above tire. I don't really need the fender hugging the tire super close - but the seatstay bridge already puts it fairly close up top and I think it wouldn't look as good tight at the top and wider at the end, would like to keep the fender fairly consistent around the tire.

Here it is with the fenders spaced out from the tire with a slightly larger than 1/4 piece of wood shim, and for reference an exactly 1/4" wood stick that will not fit between the tire and chainstay.


And fietsbob I don't quite follow what you were mentioning but this frame is vertical dropouts.