OK - I have done that. I am not great at spotting small details but as far as I can work out:
1972 - One set, Type A, no frosting
1973 - One set, Type A, no frosting
1974 - Two sets, one type A no frosting, one type B with frosting, 1/2 P also frosted
1975 - Two sets, one Type A no frosting, one type B with frosting, 1/2 P also frosted
1976 - One set, Type A no frosting.
All the type As are in my older collection, which I have had for about 15 years and came from one auction together. The two sets with type B I picked up at a different auction about 5 years ago.
I hope that helps! I admire the work you are doing on these but I'm afraid I am NOT going to become a decimal coin variation collector!