Finally made it Saturday and presented it yesterday for consumption:-
It was delicious...
I used Italian almond biscuits as the base although I had to almost double the quantity to get the coverage - I used 9oz's of biscuit.
A couple of issues came out though:-
1) I will never hand whisk cream cheese again

Took forever, but then I won't need to go to the gymn for a while... also proved to be very difficult to get a complete mix of the cheese and the eggs (I used mascapone) - some of the 'cake' tasted more of egg than cheese.
2) I use a fan assisted oven that causes me problems with timing - I usually have to down the temperature a bit or cook for a shorter time, although the outer edges of the cake were cooked and solid, the central 'disk' of mixture although cooked, didn;t set completely.
Will definitely use again.
Thanks again.
regards
Phil