This is a tough one, therer are few brown chips with spots that I could even think of that might be available in quantity. One is the California Bell $10 chip, (my avatar) which is a Gold base color. But those are not in very good condition either, they're not bike tires but they do have rounded edges, but are probably in slightly better shape to the chip in your photo above. And I would not advocate inlay replacement at all for that ship.
There were some racks darker brown hot stamp chips out there for sale on PCF the last few years, with a similar spot pattern as your chip above, as I recall they had some red ink over the spots, which may have been white or almond, and a different shade of brown. But those may have been rounded to, I'm not sure of the condition.
Good luck with your search.