Looking at the pictures provided by Bruce, and noting that there are also 48/47 varieties with 7 in middle of bottom circle of numeral 8, and also at back of bottom circle of numeral 8, I suspect that Bruce’s coin is probably the third type (Bramah 10b) with the numeral 7 towards the front of the numeral 8.
This can be confirmed if Bruce could check that his over-date matches my first picture, and then check EI of DEI to see if the small protrusions at the top of both letters are present on his coin as per my second picture.
If the above obverse ‘features’ match Bruce’s coin then let’s turn to the reverse and check to see if the B of BRITANNIAR and the E of DEF match my 3rd and 4th pictures.
If all these ‘features’ are identical then I think that we have a match for both the obverse and reverse dies.
If this is the case, and as I have now reached the 500Kb limit for this post, I can post more pictures of my full obverse /reverse which show that the top colon dot after FID did exist on the original reverse die. Whilst I think I can see remnants of the top colon dot on Bruce’s piece, it must have somehow become less obvious / missing at a later date e.g., through wear or die fill. The other 3 sets of colon dots on my own coin also seem to be identically positioned to those on Bruce’s example i.e. by way of further confirmation that both these coins have been struck from the same die pairing.