Sandboxing
I think we're all set to t39 (unless you don't want to link the two cities and want some more chops), here is the save at that point:
https://dl.dropbox.com/s/ij4wy1atcugem33...dSwordSave
The run-through is spoilered for boredom:
Finally t49 Settle C with fish improved and road in place. So one turn better, with the whip used a bit less in Agincourt but less food in the box. City B should have started a warrior rather than granary for the MP.

Then on t51 we get the third worker
The library completes eot 58 in city C (before granary)
t64 copper hooked
t65 gold hooked
t66 4th city
At three cities our costs are 2gpt, at four they jump to 5gpt, and at five to 9gpt (assuming I've got sandbox right) so I think we want to build infra and workers for a little while after city C. Also we might want to avoid building too many cottages for C - it could run scientists instead and Agincourt could do with more mines. Or we build a library in Agincourt and run scientists there, but it feels too early for two libraries.
I think we're all set to t39 (unless you don't want to link the two cities and want some more chops), here is the save at that point:
https://dl.dropbox.com/s/ij4wy1atcugem33...dSwordSave
The run-through is spoilered for boredom:

Then on t51 we get the third worker
The library completes eot 58 in city C (before granary)
t64 copper hooked
t65 gold hooked
t66 4th city
At three cities our costs are 2gpt, at four they jump to 5gpt, and at five to 9gpt (assuming I've got sandbox right) so I think we want to build infra and workers for a little while after city C. Also we might want to avoid building too many cottages for C - it could run scientists instead and Agincourt could do with more mines. Or we build a library in Agincourt and run scientists there, but it feels too early for two libraries.
Completed: RB Demogame - Gillette, PBEM46, Pitboss 13, Pitboss 18, Pitboss 30, Pitboss 31, Pitboss 38, Pitboss 42, Pitboss 46, Pitboss 52 (Pindicator's game), Pitboss 57
In progress: Rimworld
In progress: Rimworld