DECTape head problem

In debugging my DECtape interface lashup, I found that one of my head has two open windings.? Specifically, one channel has an open 'ground' with the other two lines apparently the full winding of the channel.? The second channel failing has no continuity between any of the three lines.? I have tested the other head and it has all the requisite continuity so I'm hoping I can at least get a single spindle running. Visual inspection of the head 'suggests' it might be caused by the age-old 'wire stress' of being captured within a polyester resin and then finally snapping due to internal stress.? I see lots of internal stress cracks on this head so I'm probably toast on this one. Are there documents on how the heads are made?? I.e. number of turns of number X wire; cap of X micros etc.? I'm not (yet) seriously entertaining the idea of rebuilding this head, but it looks pretty low tech.? These heads are Western Magnetic heads without a model number (only serial number 19976 - don't know the other head S/N as I haven't removed it yet.) And the look to be hand made... Has any ever attempted repair of one of these? -Gary