This one was sold at auction last summer. I found a picture of it.

Realized prices Barnebys.com

It appears to be a No.1 Lee Speed Sporting rifle in VERY nice condition.

Yours to do with as you wish, but realise that the value will take a big hit should you drill and tap for a scope.
There are zero aftermarket 'no gunsmith' scope mounts available for this receiver that I know of, past or present. A D&T side mount would be the way to go.