BaBill...;
When I picked my first of 3 of these 3-in-1 kits - I plain got 
on it!
Here's other easy tweaks, if you wish!
I discovered when Googling around that the 1B type suspension 2-wheel bogies have a visible cut-in "pocket" on the outside end of each casting which has a biggish washer and bolt nestled in it. (I apologize for the verbiage as I try to "paint the pic" in words! I'd post a pic here, but don't yet know how to...). You will quickly see these very visible details are lacking from your kit...
Now, strangely enough, while the Dragon has gone to great lengths to make so many improvements to their kits to reflect the real thing, this very cool (to me) 1B detail is still not fixed - right up to the most recent Panzerjager 1B early and Kl. PzBefWgn 1B initial kits!
It's easy to fix up - and, because the pocket is only really visible on the outside casting of each pair, you don't really have to do the inner piece - it hides behind the wheel: just carve in a little pocket on the upper end of the "casting", and set in a little bolt-head (I use a small bit of stretched sprue for this). IF you really want "the look" (really OCD or AMS), you cut out a wide "V" notch, and then use some 0.01 styrene sheet to build back the walls of the pocket more to scale - and you can add in a "washer and a nicer hex bolt-head.
The exhaust system benefits from having the "biz end" of the pipe opened up, and more so if you add on a small "flange" or "bead" around the end of the muffler "can" at the output side- the can was sheet metal and had a nicely-visible seam or flange. FYI: this same fix does great service on various other vehicles (Pz.IA, Hotchkiss and Renault tanks, etc.), with visible exhaust can ends. I glue a small strip of 0.005 styrene sheet around the muffler end to create the flange.
Another cool (IMO) little fix for Pz 1B types is to add in small weld-beads around those boxy bits and joins on the rear plates beneath the tow-pintle- I cement finely - stretched sprue into likely weld-lines and then finely ding or score it with an x-acto tip...
Enjoy! I keep "talking" about this little beast, I'll have to build another one just for this GB!
Bob