[Baertram]

I had created an addon FCOGuildLottery for some guild history related sold items (using LibHistoire) already in the pasts
It provides random dice rolls, dice rolls based on the guild member list (all members), guild member list of sold items at the guild store during a selected time frame.

As LibHistoire should capture all guild data it hopefully would collect the guild members history too, if the guild API provides that (and not only the guild roster does).
Did you check LibHistoire already if it collects this data?

Attention:
Ther was a bug at rowData.secsSinceLogoff in the past where the results were wrong if ppl have removed the account or renamed or haven't been online within the last x days. The time shown was wrong and needed to use another timestamp as offset. I do not remember the details.. Mabye sirinsidiator still knows.