Silver Jubilee Appeal Fund Crown

Hi,

it would be useful to set out the differences between the cupronickel and sterling silver versions:

a) The sterling silver version has much coarser milling (fewer grooves per mm). Images would be useful. (Pobjoy confirmed the milling difference was (is?) normal practice for their crowns. So this also applies to other IOM crowns)

b) The silver version has a thickness of 2.9mm while the CuNi version is 3.2mm thick. The listing shows identical diameters and weights. with these constraints the different densities mean that there must be a thickness difference. 

 What country? Guessing it is 1977 date? 

Assuming the unnamed coins in your post are these two:

N#7886

N#43921

Yes, it would be interesting to show the difference in surface texture.  Please add your pictures.

If you've measured the thickness of both you can submit a change request to add the thickness to the silver version and change the thickness of the Cu-Ni version.  But, just because the weights and diameters are the same it doesn't mean they must be different thicknesses. The thickness is a measurement of the rim thickness and that could be the same for both since the thickness in the field could be different to account for the same weight.