There are at least four versions of the A10A2 RF divider board, I've combined date code info from pictures of boards on the web and that messy manual pdf from 1991, the actual info the OP needs is in the 16th Feb 1984 manual changes pdf, not sure where I found that pdf;
A10A2
08460-60023 D-1339-4, D-1441-4, E-1712-4
08460-60092 service exchange by HP, rebuilt of above 08460-60023
08460-60370 A-2118-4, B-2314-10
(change 5, s/n 2118A to 2403A, from manual changes dated 16th Feb 1984)
08460-60383 ?
(change 27, s/n 2404A, s/n 2408A, from manual changes dated 16th Feb 1984)
(s/n 2520A to 2828A)
08460-60483
(s/n 2835A and above)
David
factory