Building a B-24J

 It's hard to say what happened without seeing a pic or two of the problem, but it sounds as if your on the right track thinking the paint ran. 
 Metallic(silver, aluminum,etc.)  finishes generally are a bit thin and unforgiving. Did you also spray the interior of the fuselage halves?  Sounds as if it went on heavy along the seam edges and pulled away from those edges.
 Since the halves are not joined yet, I suggest leaving the flaw alone till after the halves are together. You'll need to sand smooth the seam anyway and can smooth out the paint flaw at the same time. 
 Make sure the surface is very smooth before reapplying the paint. Metallics show scratches and dust under the paint quite easily. Many modelers will prime with a gloss black to show flaws and act as a primer before spraying on a metallic. Use an extra fine sand paper starting around an 800 grit or finer. Should be able to find sandpaper in those grits at most well stocked auto parts stores alongside the touch-up paint.  Also mask off any windows , openings, or other areas you don't want painted.
 As far as the decals, I can't think of any specific sites offhand other than Mike Grant Decals ( where I got the decals for my version of the B-24H Witchcraft ), or maybe Microscale Industries. but typing in 1/48 scale WWII aircraft lettering should give you a long list of makers and references. I often print my own markings for a particular aircraft on blank decal paper, available through Microscale or several other model supply sites and hobby shops.
 Hope this helps with your problem . Post pics of your build would really like to see it.
 Howard
 

Hey guys, thanks for the suggestions.  I've been sick for the last seven days and haven't even looked at the model.  Probably won't get back to it again before this weekend.  My original plan was to use Aluminum colored Acrylic paint for the "natural metal" surfaces.  But since I couldn't find Aluminum anything (acrylic or enamel) I used Testors Metallic Silver spray enamel.  I never thought to use a primer coat, I just sprayed it directly on to the plastic parts.  This produced a really nice looking finish on everything, except for the above mentioned runs.  I was trying to get all of the silver exterior surfaces painted before assembly so I wouldn't have to mess with masking off windows, etc.  I'd rather mask off the seams and areas that were supposed to be glued or painted a different color.  It was sprayed on in two coats so it wouldn't be to thick.  Anyway, I'll try to post some pictures when I get back to it.
 
Thanks again,
RC