Though nowhere in the league of some of the others, I had a thread going a few weeks ago on my build. I live in hotel rooms and dont have alot of tools and do this on a shoestring budget and give them away to friends. Anyway, just finished mine up. What worked quite well (givenbudget and tool limitations) was using cheap and thick water based paint like I use on the interior as a "final filler" on the cab seams as I did not want to blow out the rivet detail with sanding. Perfect? No way. Better than sanding along? Absolutely. Plastered it in paint and let it dry. Ran it under the hotel room sink and just kind of smeared things in place. Let dry. Then just used wet Q tips to remove the extra.
Also, I found the shifter tower took some trimming to get to fit well so the cab would sit flush on the rear mounts. If I had to do over again, spend time on the cab mounts, shifter base and grille alignment as soon as possible. I also put "chrome" foil on the fuel tanks, visor, battery box and over the front bumper to make it look more like a one piece style. Good luck!