Looking forward to getting the whole 1E bridged version in my hands. Have you considered doing a unique 1E adventure as part of the regular monthly DCC line? Or perhaps an OSRIC adventure? I'm not talking about a conversion of an existing module but an all new adventure. Kind of a way of injecting something a little different into the regular release schedule.
I don't presume to speak for Goodman Games, or for Joseph Goodman himself, but I can reply to this as I have done some checking into this very thing myself. These comments reflect my opinion (and only my opinion).
No one outside of WoTC can legally do a true 1E AD&D(t) adventure. WoTC owns most of the intellectual property associated with the former TSR organization, and such IP is protected under US law. And while there are a variety of opinions on whether this protection is enforceable or defendable or not, it is clear that the IP belongs to WoTC.
The d20 OGL doesn't expressly cover 1E, so there's little wiggle room in the OGL itself.
The Goodman Games special convention releases are a bit unique. We steer clear of any potential trademarked names, descriptions, and such. We avoid the artistic presentation or representation which might in and of itself be protected IP.
There are a few publishers out there that are for all intents and purposes publishing 1E adventures. But, they aren't doing so legally as licensees of WoTC.
OSRIC releases are kind of unique, too. The OSRIC OGL draws from WoTC's OGL, but comes up with a different set of rules that happens to function a lot like 1E. Publishers like Goodman Games, Expeditious Retreat, and others have to decide whether publishing under OSRIC is a direction in which they want to go or not. Goodman Games has decided, at least up to this point, that they will not be publishing anything under the OSRIC OGL, or which is expressly OSRIC-compatible.
Then there's the matter of confusion in the market place. The DCC line does a good job of recreating the look and feel of the old 1E modules. So good, in fact, that many retail consumers believe that the DCC line of adventures are in fact re-releases of the 1E modules updated for the D&D 3.5 rules. As crazy as this sounds, especially since the cover art is all new for the DCC line and since the title of each adventure is right there on the front cover, it does happen. I saw it at Gen Con last year, at the Goodman booth, and I've heard the same comments from the guys that run our FLGS. Adding a sub-line of 1E DCC's would in all liklihood add further confusion to this problem.
Sorry the news isn't better on this front. I feel your pain!