Second the call to Mossberg. I needed replacement screws for my 464 .30-30 and they sent them at no charge.
Plate, screw and detent are there, yup all you need is the button.
Replaced quite a few with plastic or aluminum of standard design, no problems.
Might want an offset one if planning on scoping it for deer hunting
Cantilevers usually place the scope way too high (even with higher comb stocks), they tend to not be the great fix many think.
Why did you need "replacement" screws for your 464?
I thought that was basically a brand new model.
I had one just break in half while shooting one day I called Mossberg just to ask where I could buy one and they sent me a new one in about a week. Plate and detent included.Call mossburg. they will send you one