How to put 4 monitors in one X screen?

Question

linux

Good day to all!
Situation:
There is a PC with rhel6 based OS installed, 2 Nvidia GT610 graphics cards, proprietary drivers, 4 monitors connected (2 on top, connected to GPU0, 2 on the bottom, connected to GPU1).
Monitors are merged into 2 xscreens (X screen 0 for top, X screen 1 for bottom), xinerama enabled.
When connected to this PC via vnc (I tried x11vnc, vino, tigervnc, tightvnc servers), mouse control works only on 2 monitors (which are in X screen 0).
People who know, advise how you can put all 4 monitors (I remind you, they are connected to 2 different video cards) into one virtual X screen? Well, or tell me, maybe there is some kind of vnc server that can do 2 X screen?
X forwarding via ssh is not suitable for political reasons, xdmcp is the same.
UPD
Issue resolved. If you are interested - write here in the answers.

Answer 1

You can run two x11vnc processes on different ports, for example screen :0 on port 5900 and screen :1 on port 5901. Run two vnc clients and control all screens.