I'd never heard of the cartridge before either. I looked in a couple of my manuals, and didn't have any load data for it. But the data is no doubt out there some where.
I then looked in my Midway catalog and found brass for a 7x61 Sharp and Hart, which led me to this, it looks like a great cartridge. Tho it seems that today it's a hand load only cartridge
7×61mm Sharpe & Hart - Wikipedia, the free encyclopedia