Bow: As Jmoore says, the Canadians used a variety of mounts and actually did mount Lyman Alaskans (7/8inch tube) in the more common Britishmount/bracket with "bushings" (see picture on pg. 40 of "Without Warning" by Clive Law. Not being a machinist I have no idea how difficult it would be to make a facsimile of those bushings. I use a one inch Weaver on my "replica" 4T but also have a replica #32 to make it look more accurate.
Ridolpho