This has been a desire/issue since RoI was released ... at that time data.lotro.com "broke," i.e. it was not updated with the RoI items.
Originally Posted by Nakiami
I haven't done any kind of exhaustive search since after Update 9 released (and the maintenance was completed) however,
the number of "grey" (i.e. default) items at my.lotro.com in character sheets for my toons has decreased dramatically!
(Currently, they are all equipped with Great River gear for the most part.)
Does that imply a more current data.lotro.com? At this time I do not know -- it seems to be.
I also have not checked lotrodata.com for current information. He does (or did) do a regular extraction.
In my collection of "useful tidbits" --
Level 85 Armour
Level 85 Jewelry
Returns quite a bit of information. However, I have no idea if it is complete or not as I have not looked to see what items that I am aware of are included or missing from it. I'm not certain what you mean by "horse-lords armour," I haven't encountered that particular name for an item.
BTW, I assume you realize that the lorebook is a Media WIKI and is available via the Media Wiki api.
Bill Magill - Mac Player - Old Timers Guild- Gladden:
Valamar: Dwarf Hunter - Level 105
Valdicta: Dwarf Rune-keeper - Level 105
Valanne: Beorning - Level 91