These horns are extremely rare (I know; this is a phrase that you'll hear often about the Martin models).

According to all the posts I have seen about these horns, these horns were supposed to be "watered down" versions of the Handcraft Committee II. I dispute that somewhat: the horn look more like is a Handcraft Imperial body (note the position of the Eb vent key, below the low D key) with (mostly) Handcraft Imperial keywork.

In other words, it's just a relabeled horn with some keywork tweaks.

HOWEVER, the Handcraft Standard Special version of these horns have a body that is more Handcraft Committee-like: they don't have the odd Eb vent -- but the Handcraft Imperial does.

Given the lack of ornate engraving and the missing adjustable RH thumbrest on both models, I can agree that these are "watered down" horns, but not "watered down" Handcraft Committee II's.

It is probable that these horns were marketed either as intermediate models, or a non-pro-pro alternative (such as the Yamaha 62 is to the Yamaha 875). I would suggest, however, considering the horn does appear to be based on older tooling, to play-test these models for a long while before buying.