Redfield "vintage" rear sight

[MLC]

I bought my brother a Winchester model 75 recently.
It is missing the rear aperture insert for the Redfield sight.
Are all Redfield rear sights standard?
It came with several front sight inserts, should I try to find a rear set instead of a single rear aperture?

 

[nesikabay]

Re: Redfield "vintage" rear sight

Brownells sells the rear disc.

 

[MLC]

Re: Redfield "vintage" rear sight

I'm looking for the rear peep sight insert.
The sight has micrometer windage and elevation knobs.

I just found an image on Ebay, apparently it's a Redfield model 75.