I took a couple of pictures as a visual aid. Do not have an Interarms to compare to, but the Pre64 Winchesters should illustrate it well enough.

Original .30-06 (1954) Action is here.

Original .375 H&H (1955) Action is here.

The bolts side by side are here.

Obviously the magazines are different, as are the feed rails. You can see from the pictures how Winchester got the .375 to feed into the magazine by trimming the rear ring back for the longer cartridge. I would imagine all that is needed for the Lott conversion on the Interarms would be some similar feed rail modification for the longer cartridge, some trimming of the rear reciever ring, and a longer magazine box.