Hi BB, from my records, the model 450407 was originally fitted with the Kirby Lauson...whether this machine actually was....remains a mystery....as it has a later model Briggs fitted....
You are correct about the lower legs...but I have seen another machine on this forum, with supposedly the original Kirby, had the bent lower legs of the Briggs version.
Maybe when the machines were erected, they just grabbed what was to hand... wink
cheers

Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member.
Kindest Regards, Darryl grin