Geographical Congress Colour Shift Stamp
Please can anyone offer an opinion as to the value of a 1964 geographical 2 1/2d Un-mounted Mint (NHM) stamp.
From the picture the top stamp is the expected presentation. The lower stamp has the 'yellow' shifted down along with the 'Black' towers and graphics
The yellow shifted down now partially covers the '20th' white text & the colours become unmixed leaving a 'Blue' outline of the spikes where it should be green.
Reviewing the 3 towers position will show the drop of the towers as a comparison from the expected.