Matt L.;
Yes, the 223 were built up using the current-serie 222 bodies, with modifications to the roof for the smaller turret, addition of the frame antenna and its mounts and operating system, installation of a substantial radio set and all the related hardware, and a different pedestal for that dinkier 223 turret. There were a bunch of interior detail mods - deletion of the 2cm ammo racks and such, addition of a storage bin and a small map table and a jump seat, etc. Basically, a 223 was a down-gunned 222 with addition of a radio suite - and not a reworked 221 (even though the 223 also had a tiny MG turret, like that 221. The hull and interior were different.) And 223 were produced even after the 222 had stopped production, while the 221 went out of production much earlier in the war.
I loved the first HB 223 model, albeit HB really did blow both the interior (no radio suite, etc.! Lots of other wrong stuff) AND the frame antenna and its mounts. Basically, HB gave us a late-war serie-5 223 hull with an earlier-war frame antenna and mounts. I ended up scratching in part of the radio-racks, the map table, the jump seat and other stuff in back and the radio op's seat and map table up front, and a whole new antenna system.
I'm hoping that HB includes an interior in this new kit - they almost have to, given it is visible through the turret and roof whether the hull doors are closed or not. And they have been generous with their other 22x kits in this regard. I really hope that this time they give us some radio racks and stuff, this being a radio car, after all!

I don't expect that the interior will be very accurate, albeit hope springs eternal.
Another, more subtle area of concern is the suspension... Which version will HB include?
But regardless, whether one obsesses and tries to fix it for accuracy or just builds it up "as is", these SdKfz 22x kits are a lot of solid modeling pleasure in my opinion, and there's plenty to fiddle with for those who wish to. I'm pretty sure that HB will keep pretty much to their established form with this one, and I'll probably get one to add to my future Viking send-off, if not to actually build!
Bob