Ok, Express and Peep sights it is. Thanks for the input.

Now that I've got taken care of that concern I have a bigger problem.

What Peep sight to use?
The guns will be styled like late 1920s, 1930s Holland Rifles, Holland's stepped barrel with short 1/4 rib & one standing & one folding, Holland style stock and Flag safety ect.

I want to be able to use the Express sights sometimes.

I like the Lyman 48 as it mounts on the right side of the receiver and the eye piece (I can't remember what it's called) can be removed and replaced without major zero loss.

But the problem is, I don't think it is period correct the British Express Rifle style.

Other than the Rigby Striker mounted Peep, what did the Britsh gun trade use?
Ideally some form of a receiver mounted, click adjustable sight.

I've been looking on the web but have not found much. Suggestions and pictures links?

Allen