Scope Risers / Misc. Optics Mounts

[LAZY EYED SNIPER]

Have any questions about Scope Risers or Misc. Mounts? Is there a particular model you like to use? Let's see some pics and discussion...

 

[E350]

The receivers on both my 835 and 935 are factory drilled and tapped for scope mounts. There are two pair of two holes each. Does anyone know how far apart center to center the two holes are in each pair?

Also does anyone know the part number of the Weaver See-Thru Rings, if any, which would mount on the receiver (without using a Weaver or Picatinny a base)?

 

[Pookanator]

Can a riser be used to mount a short red dot or reflex site it a 464? Mount the rise below, for example, and mount it on the Weaver bases.

 

[melomanic]

I am looking for a picatinny rail mount for a 590. Found the UTG and several ones from Weaver. Could you recommend one of those or even another one I didn't mention here?
Is there any rail in marine coat finish?
Same for a heat shield...could you recommend one? Also I would prefer one in a marine coat finish.