Goodman Games

Did any of the other dragonmech books ever become PDFs I can buy and download other than rumors/lies?

They were pdfs but with the ending of the d20 system license they have been removed. Or at least I assume that is why they were removed. They could be modified to removed the d20 system logo and other things allowed by the d20 system license but I don't think that is being done. I'm not sure how well they sell so it might not be worth it to invest the time to do so at least in the short term. My biggest complaint about 4E has been the ending of the d20 system license. Dragonmech, Morningstar, Old DCCs, Dragonstar, Mightnight and other products are no longer available in pdf. I don't have the space for large rpg collections anymore. Luckily I picked up the Dragonmech material before it disappeared. Wish I had pickup so of the other stuff.

Well that sucks.

What about this:
http://e23.sjgames.com/item.html?id=RADM01

Is this an error? I guess I'd better buy it before it goes away...

That's technically a Ronin Arts product produced with a license to the Dragonmech setting from Goodman Games. Some companies have been removing the d20 system license products. Others have been replacing the logo and updating the product to just OGL. Finally some haven't done anything. I suspect the latter may be in violation of the license but many of the small publishers are probably not worth bothering to go after. So may not even exist anymore. For example I wonder about Behemoth3, Inc. since they have no website and haven't had any new products since 2004. (I don't know if they are using d20 system license. They just happen to be a company I've looked at which appears to no longer be active.)