Just to confuse things even more, Irwin wasn't the only one to put his logo on a modded ax - look at the headstock of
Phil's Guld (though I must add, I haven't heard them claim it as their creation).
Since the eagle logo replaced the peacock & Alembic logos on Wolf about '74, and Hi-A didn't make mono p/ups until '75 (I'm assuming a hex would need more than a 1/4 jack), the mods were done at least 2 years after Jerry is supposed to have given to Ramrod.
I seem to recall reading here somewhere (can't find it) that they made at least 6 for him, so, taking Mica's word that 25 is Wolf, and knowing where 13 is, this could be 03, 05-07, 09, 11, 18, or 20-24.
Peter