No wires on R of the dial. What is shown in the diagram are the off-normal (ON) contact springs which close when the dial is operated.
R----------X---------BK
With the line wire disconnected, you should measure continuity from L2 to C with the phone off-hook.
That is the path from L2 through the yellow mounting cord conductor to Y, through Y and BK of the hookswitch, the jumper from BK of the hookswitch to Y on the dial, and through the dial pulse contacts to BK on the dial, through the black mounting cord connector to 2 on the terminal strip, and through the (brown) jumper to C on the network.
There should also be continuity between GN on the network and the white receiver lead, while the phone off-hook and the line disconnected.
That is from the receiver, through the wiring inside the handset to W in the handset, through the white handset cord to W on the dial, through the dial ON contact springs to BB on the dial, through the jumper from BB on the dial to W on the hookswitch, through the hookswitch to GN terminal, through the green mounting cord lead, to GN on the network.
You can also try moving the red line wire from L2 to C, which bypasses the dial pulsing contacts and the Y-BK hookswitch leads.
If there is still no dial tone, connect the handset directly to the network:
White (receiver) to GN
Black (transmitter) to B
Red (common) to R