Hi Steve.
I am very sorry to hear of the passing of Colin.
Like you, I have not known him very long and not actually met him in the flesh, but did find him very enthusiastic and helpful.
We did exchange some information about London Trams and local South East London history, then more recently the PLA railways and he emailed me the Millwall Circle article. One of our other club members thirty2a also had dealings with Colin about the trams, so he will also be sorry to hear about this.
Colin had been a member of the Carshalton and Sutton Model Railway Club, so I hope that someone from there will pick up on this, possibly Dave Smith.
All the best
Ray Blanchard