These units are being sold AS-IS for parts or repair. The A-unit shell is a 2353 with louvered roof but the chassis on both the A&B are probably from another F-3 as they have black trucks and pilots where they should be silver. The B-unit chassis is marked 2343C and the shell has the screen roof vents. The A-unit has battery damage and is missing the thumb screw that holds the battery cover closed. The A-unit does have the twin horizontal motors. The A-unit did move slightly when we first tried it but now it does not move. It probably just needs to have the E-unit cleaned and the motors serviced. The A-unit shell is missing the clips at the back to hold the shell on to the chassis. The B-unit is missing one porthole window and has a slight sag in the roof right about the middle, on the edge.