New 20 ounce tumblers available now! Forum donation credit with purchase. https://www.wildguzzi.com/Products/products.htm#Tumbler
Another vendor.https://www.amazon.com/Universal-Motorcycle-Fork-Boot-Set/dp/B00TQBL52G/ref=pd_ybh_a_113?_encoding=UTF8&psc=1&refRID=3XR3HVJPGDJXTGJB6YCZ
Those may be a bit small. The Triumph ones I linked are 40mm upper ID, 60mm lower ID, 75mm compressed height, 200 max height, 150mm static height.Our forks are 45mm and the the fork sliders are about 63mm I think.
I used the Triumph gaiters too and did not trim any off. I loosened up the clamp on the fender between the forks and worked the gaiter down a bit.I got these. They were a little tight but streched out ok. I put a small hole at the back bottom of the gaiter to let it breathe.https://www.ebay.com/itm/Triumph-BONNEVILLE-THRUXTON-T100-Fork-Boots-Fork-Gaitors-OE-A9638018/162276226225