Bill
Many that I know still use their MVA, Lee Shaver Soule sights with a Hadley eye cup using the larger eye apature, and then I know some that remove the eye cup all together and use the threaded hole as a peep, and don't change them out for the Lyman peep sight. A friend of mine has a C. Sharps Sporting peep sight and front globe sight with center fixed post. He has found that this combination causes his 26 or 28" C Sharps to shoot 10" to high at 100 yards. Obviously not the right combination of sights for his Sharps 45-70.
I have a buckhorn elevator sight #102 by Shiloh on my Sharps and just change out the front insert to the low post insert for hunting that I will use.
If after range testing this doesn't give me the accuracy that I want... causing too high or too low of hits, I will change out the front globe and use my front blade sight in combination with my rear buckhorn sight.