Like it was custom made to fit.

That little Yaesu FT-450D radio I'd picked up last week is so portable that it warrants its own carry bag.  So I measured it and started casually looking around for something suitable.  BTW and for reference, including all knobs, heat sinks, etc. its outer dimensions are 6 1/4" wide, 1 3/4" thick, and 11 long.  Didn't take long to find what I was after down at the Army-Navy store:

Here's a link to the exact model.  Quoted dimensions are 7 1/2" wide, 1 3/4" thick, and 11 1/2" long, but it's actually a bit thicker, maybe a little over 2".  The point is, the radio fits, and it'll almost certainly still fit with these side rails (not the one with the battery box, scroll down; black, please) attached to keep from dinging vital parts.  And that little front pocket with the pad and pen in the picture?  Perfect to keep the microphone under control.  Comes in your choice of colors, as long as it's something drab.  I went with the almost-white khaki, mainly to keep the contents cooler if left in the sun.

No, you can't operate with the radio still in the bag.  Don't be a dumbass, it would block airflow and cook the thing, you couldn't get to the coax connectors on back, and the speaker would be covered and mghlphffed.  This bag is just to carry things, and to keep them from getting dirty and scratched while you're out roughing it.  Also to note, very little else will fit in the bag.  Conveniently the MFJ-939Y and LDG YT100 tuners look like they'll fit into another copy of this bag too.

Anyway, it's a near-custom fit for comfortably under $20.  This is a good world.