I'm jealous. I have looked and looked for a 115, every time I come on to a Tiffany, I go into my secret mode .
slowly look under the bed, pretending to be looking to see if it has a bobbin. yet making sure no one see's me. when digging in the Fred stash, two Tiffany's , rats !!! They are both just plain ol 15"s.
I brought them home any way.
It looks like you have real good color it that one, be careful the color on these wash away real easy, even just using SM oil
I take it this is your first treadle, this new belt. The tighter the belt, once installed, the harder it will be to treadle. You want a semi loose belt. plan on readjusting it several times when new. in other words poking new holes.
don't toss your old belt away, unless it breaking in short pieces like 6". I have have and use belts made up of pieces of old ones, one is made of about 6 pieces and works good
if it's a belt that looks like it's coating with something shinny ( shellac ? ) I've found those will slip, so I have been using sand papar and removing the shinny glaze