A broad view.

Interesting coat of arms, eh?

Last photo. The letters C and K intertwined and they seem to be embellished with a train-track motif.

Why do you think it's brass? I would bet it's silver, and in doing a little search found this:

Here is a link that might be useful: ommentary on similar article with identical hallmarks

Here's the nearest thing I could find like your tankard. It appears to differ in that its side is slightly curved whereas yours is straight sided.

Here is a link that might be useful: Pewter Pint Tankard

Did you look at the pint pot in the link I posted, jemdandy? Identical design and hallmarks.

No, I did not notice your pink pot. However, while fishing on the internet, it seems that the Forest Gate Railway Tavern went out of business and has been revived as a new business.