All Lee Speeds were made by BSA, and retailed by the trade. Army & Navy and WW Greener appear to have made a specialty of them, and I have also seen William, Moore & Grey, and Alex Martin marked rifles. Most retailers would have listed the Lee Speed in some form or another in their catalogues around the turn of the previous century.

Standard chamberings were .303, .375 NE, 7mm and 8mm Mauser (flanged), and .405 Winchester. All these cartridges were loaded by Kynoch at the time.

We can be reasonably confident that Army & Navy would have carried, or had available on order, the full range of chamberings and grades.

I have seen a reasonably history of A&N somewhere, will have a look through the library on the weekend.