I remember visiting their premises in the Tottenham area some 25 years ago, but could not remember what they had changed their name to, so I Google'd them.

Try http://www.exterionmedia.com/uk/our-products/bus-advertising

Might be worth contacting them, seeing if they can help and what they have on file. I'm sure they will have some information somewhere.


UPDATE - I have just found this page that gives the sizes
http://www.exterionmedia.com/uk/our-products/production-library
but the link to 'Routemaster' is not the vehicle that we know .....
(was that politically correct enough .... ?
Click on "L-sides".

My bus number (if any): RM1368

Thanks Andrew for the link, That gives this me the total N/S board dimensions of the NBFL LT type as 722 cm x 60cm with a display area of 715.6cm X 53.6cm,I hope that is what the RMs had !

I have the backing material make and supplier and we know the joining strip type thanks Mark, but a precise thickness measurement would be good as it's important!

My bus number (if any): RTL 960, RMC 1458, RM 1585 and several RTs

Brian - From the "L-sides" file, the display size without the lower panel would be 7.222 x 0.601m and I think this was the nearside advert.

Perhaps somebody can confirm ?

My bus number (if any): RM1368

Thanks Andrew lower down there is a link to the ads for the "Routemaster" that shows the N/S as 7220mm x 600mm which seems to be right, but I would like confirmation if anyone has the actual RM/L sizes
Thanks for the interest and help!

My bus number (if any): RTL 960, RMC 1458, RM 1585 and several RTs