I believe this is Canadian western red spring wheat flour traditionally. Hi protein content. Used in Italy for pizza et al.
Are you channeling your best self with this comment? (If you're not sure, check out our Code of Conduct.)
Going to ask a silly question here - what is manitoba flour?
Now embarrased because I saw the rest of the question. I think red spring wheat is the same whether in Canada or US. I recommend googling red wheat flour.
I found it finally. Teitle Bros. in the Bronx. Ask for Eddie. He either has it in stock or can get it. (718) 733-9400