Reviresco Austin Armoured Car

I wanted to test my skills with an airbrush I was given some years ago; I've never used one. I thought I'd knock this kit together in a few minutes, straight out of the box, as they say (although it comes in a polythene bag, not a box). It took about half an hour to get it to look like this:

Despite my intention to build it OOB, warts-and-all, and only use it for "target practice" while I learn how to use the airbrush, I couldn't resist "fiddling" with it. I've left off the front mudguards because they looked awful, and I am going to use the Hotchkiss MGs from the Emhar Mk IV female tank instead of this kit's unidentifiable blobs. I feel like I should fill the great big gaps with Green Stuff. Sadly there's nothing I can do about the rear end; it's completely the wrong shape (well, I could do a "cut and shut" on the chassis, and saw off the rear corners, but... it's only for paint practice!).

I carried out the machine gun transplant (the Emhar Mk IV female should not have Hotchkiss MGs, so it was no big deal to cut them off and use them here):