Not into buses or trains but found this among the huge John King bequest.
From
@Blitzwalker and
@GlassHalfFull we learn it is a slipboard used on RT buses in the 50s and 60s
@GlassHalfFull says that special 161 buses were advertised in 50s and 60s programmes that ran from Sidcup garage to Charlton, beyond their usual terminus in Woolwich.
As John King lived in Eltham it's possible, speculates
@GlassHalfFull that this is where he got it.
Similar places of interest boards could be seen at the front of these buses as shown in this pic from
@Blitzwalker No real monatery value, you can buy similar on eBay for £6.99 but an oddity from local history
Comments
If it is available for purchase, and anything else of transport interest, please let me know.
I took a quick random look at the 1961-1964 era and each of the programmes has a small panel in the centre pages, where I thought it would be. CAFC vs Plymouth Argyle 16 Mar 63. (We won 6-3 on a lake in a monsoon.
SPECIAL BUSES TO THE VALLEY
Special London Transport buses for Charlton supporters will run on Saturday home League dates throughout the season.
Two there-and-back trips, serving 12 points in the south-east suburbs, will run at special bargain fares.
Starting point for the first trip is Sidcup bus garage, picking up at Sidcup High Street, Chislehurst War Memorial, Mottingham Road, Mottingham Station, and Eltham Church.
The second trip starts from Bromley bus garage, and has additional picking-up points at Bromley High Street, (Gaumont Cinema), Downham Way, Grove Park bus station, Baring Road, and Lee Green.
The return fares range from 4/- to 3/-, with half price for Under 14 fans.
Thanks to @blitzwalker
Then thinking on it so was the 75 bus to Charlton village and that had come from Croydon ( make of that what you will).
Yours for £60 at https://www.loveantiques.com/items/listings/london-transport-slipboard-poster-used-on-rt-type-bus-LA212434