Below is a copy of the Ulster Barlows from the 1960 Ulster catalog.
The #10 with a clip blade, #11 with a spear blade and the #12 with a sheepfoot blade.
The 10OT Barlow is consistent with the Clip blade in the #10 Ulster Barlow.
I would think that a 12OT Barlow would be consistent with the #12 Ulster Barlow and have a sheepfoot blade.
I do have a note, as I recall it came from some discussion on the early model numbers.
I found the post where it is listed, by dlk, 8/31/05.
http://www.bladeforums.com/forums/showthread.php?t=362762&highlight=12ot+barlow
The best info I have found so far on the 12OT Barlow is in this thread.
Note the post by Larry (lrv). This documents the source of our information on the 12OT Barlow.
http://www.bladeforums.com/forums/showthread.php?t=386890&highlight=12ot+barlow
More research from Larry (lrv) on Old Timers and a mention of the 12OT Barlow:
http://www.bladeforums.com/forums/showthread.php?t=439424&highlight=12ot+barlow
After spending 2 or 3 hours buried deep in the archives, all I have found out is that the little bit we know about the 12OT Barlow, seems to come from Debbie Chase, a former Schrade employee.
It seems that the 12OT Barlow was made for the European market c. 1964-1965.
That seems to be all the info I can dig out of the archives on the matter.
Perhaps Larry (lrv) has learned something else about the 12OT Barlow since his post 3 1/2 years ago.
Dale