Here are the Coinage figures, taken from “A New History of the Royal Mint” edited by C.E.Challis.
1992. page 368 Table 46, - The Coinage of Halfpence and Farthings, 1672 – 1676 [March 1679].
Source PRO. E351/2122,2123,2124; CSP Domestic 1676-7; CTB, 1676-9, 1266-7.
£
s
d
total d
10/08/1672
25/01/1673
10,928
14
11.75
2,622,900
10/02/1673
12/04/1673
1,654
8
7.75
397,064
13/04/1673
19/04/1673
47
7
2.5
11,367
20/04/1673
20/07/1674
10,821
2
5.25
2,597,069
21/07/1674
22/02/1676
16,801
3
7.75
4,032,284
March 1679
1,409
338,160
Totals
9,998,843
This was part of a conversation I had with a former member (Teg) when we were discussing mintages of Charles II coppers. I also made a list of clearly identifiable coins taken from catalogues at the time to analyse the date distribution.
I don't have a copy of the book, though others do. There might be further mintage figures listed. Using these figures inconjunction with other musings such as the info that there were 5 presses and by extension 1 striking halfpennies and 4 farthing, it was possible to produce a reasonable guesstimate of mintages.