Auxilliary Trans. on BF Avery

[Eric Severance]

I recently picked up a 1944 BF Avery model A (looks identical to GG General, only red) with a two speed underdrive auxilliary transmission. This transmission looks to me like a factory option or a factory built  aftermarket option. It does not look home made at all. It does not show up as a factory option in any of the Avery or GG parts books that I have looked through. I have spoken with two local experts and they have said that this option was available, and between the two of them they had only ever seen two not counting mine. I have looked through many of the posts here, and none of the pictures of the trasco made trannys resemble mine. I would like to find some literature about these, and possibly a picture or two, so I can fix the shifting linkage on mine (which is missing). Any info would be much appreciated. Thanks,   Esev