Top stamp! But not really an actual stamp.
I’m no stamp collector but this one is ace. I had to call on a philatelist or 2 to help me out on this and the info they kindly gave me is below.
The stamp is one of an extensive series, featuring locations served by various railway companies. The artwork on the bunch I have seen is so cool. There were apparently three issues of this one. One in the 1930s, one in the early 1950s and one in the 1960s (which was a straight reprint of the 1930s one, but apparently the 1930s one is not perforated ). I have managed to get a few of these and the ones I have are said to be reprints from the 60s (of the original 30s one). The 50s one had a different image. They are only worth a few quid, but a must for a collector. Right?
Basically these stamps fall in the group of the Cinderella stamps. A descriptive to cover lots of stamps that aren’t really stamps. This thing had no postal value and was sold to put on a parcel as a piece of art. It’s actual descriptive term, in this case, is a poster stamp. So it was just purchased alongside your stamp to look nice or your package (and make a few bob for those who sold it, in this instance the GWR).
I think its totally ace!