b-18

No, joe, no Bolo. (I couldn't resist !)

The B-18 was based on the Douglas DC-2 (which differs from the DC-3), and I believe that I have seen a DC-2 kit (maybe Williams Brothers?). I don't know of any conversions, though.
Good luck. Hope you find something you can use.

Actually,... for the B-18A Bolo

Airmodel, Execuform, O'Neill, and White Eagle all made vacuform versions of the B-18A Bolo in 1/72 scale;

and...

Combat (now Roberts) Models used to make a vacuform version at 1/48 scale. Haven't seen it on their website, but if there's enough interest (and if they still have the ability to make the form), I'd think these guys might be able to get us a few if enough of us ask. Dunno fer sure. Would have to ask.

No one has made a plastic injection-molded or resin version of this plane at any scale.

...for the DC-2

A number of manufacturer have made a 1/72 version and even a few at 1/144. Mostly vacuform.
MPM used to make a USN/USMC DC-2 plastic injection-molded kit (#72091) at 1/72, might be one under their Condor label they started in 1993.
Pioneer and RVHP both made a resin kits at 1/72.

As for conversions... I don't do conversions.

Hmmm... i've never seen a B-18 on the shelf, before, or heard anyone who built one... sounds like an interesting project! Didn't the B-18 "win" the USAAF bomber competition by default when the Boeing 299 crashed?

I just ordered on in 1/72 scale a vacumn formed Its available from aviation USK Nebraska The kit number is EX-01 and its $16.25 While theres an online catalog with no online ordering system you can call 402-932-8875 to order

thankyou, found the execuform kit at the aviation usk nebraska site and will be ordering it. now to find the correct markings........................

thanks again.

joe