Hi BB,
Looking over the photos again, I feel that the bolted on catcher rubbers were the result of a previous tenants 'improvements'. Maybe one of the spot welded lugs separated from the side frame, and they decided to change both to bolt on....
It is definitely an early Scott Bonnar Model 45, Series 2 twin rail chassis, as evidenced by the double riveted ID plates, and I agree with you that it has had a repaint at some stage as well as a after-market (or homemade) catcher fitted.
It appears it has had a hard life...but can be restored to its former glory with a little TLC. 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