As far as I know, currently the only information available about older revisions of a filter are those from a query such as
https://en.wikipedia.org/w/api.php?action=query&list=logevents&format=jsonfm&leprop=ids|title|type|user|userid|timestamp|comment|parsedcomment|details|tags&leaction=abusefilter/modify&lelimit=2
which returns a list of objects like this:

{
  "logid": 50427214,
  "pageid": 0,
  "ns": -1,
  "title": "Special:AbuseFilter/345",
  "type": "abusefilter",
  "action": "modify",
  "0": "11627",
  "1": "345",
  "user": "Salix alba",
  "userid": "212526",
  "timestamp": "2013-08-13T10:59:54Z",
  "comment": "",
  "parsedcomment": "",
  "tags": []
}

But in order to get better statistics¹ than those provided by Abusefilter (which only provides a total "Hit count" for each filter, not separated by the filter version), I need to get all the parameters which are visible on pages such as
https://en.wikipedia.org/wiki/Special:AbuseFilter/history/345/item/11627
(particularly the conditions and actions taken by that version)

This is further complicated by T54221 and T54919.

¹ E.g.: https://pt.wikipedia.org/w/index.php?oldid=36678888&uselang=en#Julho_de_2013