What I have here is a proper, original Lee Speed Sporter .375 Express in no.1 pattern including full rib and express sights etc.

25" barrel
Muzzle diameter is .657"
Diameter at horn forend tip is .739"
15-3/4" from muzzle to forend tip.
It's a straight taper from muzzle back about 20"

That's a start.
I can do photos and more detail from action ring forward another time, too busy today for that.

Hope this helps, stay tuned for more info.

Cheers
Tinker