Does anyone know if its possible to date a Lee Speed sporter by the serial numbers stamped on the underside of the action and barrel?

If this isn't know, is there any time line in regard to what features, e.g. bolt/rifle without any safety, bolt with safety on striker, safety on side of action that would help date when a rifle was produced.

I really only need to know if its pre 1900 or after.

thanks,
Ron.