Have 36" Woodland Pro branded Cannon (I believe it's a Superbar) with an S2 mount : 404 x 063 replaceable sprocket nose. If it's not new, it's dangerously close.
Looks like it's drilled for two different mounts.
Have kept it thinking I'd use it some day. Have had a few 066/660 saws around over the years. One had a big bore. Never did get this bar out.
Have a 500i on order and doubt I'll use it on that saw either.
Hopefully one of the other offers work out. This thing has been hanging here so long it's part of the essence of the garage.
~EDIT~ Sorry, looks like the S2 is for large mount saws.