Yes, the 8x50 was a Lee Speed chambering, I think Taylor mentioned it in African Rifles......

I had a beautiful example in my hands once a few years ago. It was marked 8m/m 2.06".

I was so P.O.'d that it wasn't a 303 as promised by the seller that I returned it!

I know, never been accused of being overly bright.....................

Can't help you with a parent case, but I think Buffalo Arms has what you want.

SOS