I was wondering if anyone had any info.. this would be regarding the 28" canadian size (typically 28 X 1 1/2) found on most old cruisers.

1: Did they ever produce white walls in this size?
2: Does 28 X 1 3/4 exist? I found a photo which shows 2 CCM Flytes with riders on them, one of them clearly has beefier tyres which look like 28 X 1 3/4.. was this size ever sold on bicycles or otherwise? If so what would the chances of finding a pair be? I imagine slim to none..?!

Oh ok, its not just regarding the canadian type. I have a "raleigh roadster" tyre tread which is 28 X 1 1/2 but it doesnt fit (too big for the rim) I guess because its english, and the fractional size is what counts (635mm) Where on earth could I find a rim to put this tread to use (i would prefer a rear rim.. a coaster brake would be neat, but I imagine most old english bikes never used em).

All your questions are answered here:

https://www.sheldonbrown.com/tire-sizing.html

Yeh.. I know about that site, and it doesnt answer any of my questions.

Sheldon Brown's website has a conversion chart that enables you to "convert" the old style size into a modern metric size. His store can get you tires for any rim that was "popular" in the past fifty years, IF you figure out the correct size.

Assuming you have some of the "old" tires, you could take them to a bike shop that stocks a wide variety of "oddball" sizes, and look for a modern match.

To answer your question--did they ever make WWs in the 28" canadain size---yes(still do!)Did they come in fatter sizes ---yes(still do)--"For the rest of the story"(Pall Harvey)The Cruzer 28" canadain tires are 700s.So 700X35 will work just great.Or 700X40
Yellow Jersey.com has the English rims.English coasters came spoked for 40 hole rims(which they will be).

Ok.. so where do I get these?!

Ask oldy57
look down the post a bit he's on this forum

Never mind then. Ask somebody else.