Band on my BS 510 is .375" wide, .016" thick. Ends of the band are folded over and drilled for attachment. I didn't measure length.
The MSC part number I had was 79287264 for the O-rings. https://www.mscdirect.com/product/details/79287264?rItem=79287264
However these are ~.275" cross-section, where the true B&S ones (somewhat worn, but came with my machine) are .250" cross-section. So they're not a great fit, and drag in the pulleys. Maybe over time they'd "wear in" to size.
I think Bourn and Koch wanted $24 per O-ring when I checked a few years back.
The MSC part number I had was 79287264 for the O-rings. https://www.mscdirect.com/product/details/79287264?rItem=79287264
However these are ~.275" cross-section, where the true B&S ones (somewhat worn, but came with my machine) are .250" cross-section. So they're not a great fit, and drag in the pulleys. Maybe over time they'd "wear in" to size.
I think Bourn and Koch wanted $24 per O-ring when I checked a few years back.