I have been finally able to prime my models, as the weather has been warm today. Attached are the primed insides of the Hanomag Sdkfz. 251/8.
The primer did not bleed through the shirt material I used for the roof. This bodes well for when I prime the outside.
Now I can paint the inside of the halftrack. This thread on Sdkfz. 251 interior colors exists, but the answer hasn’t been found concretely yet. Also, since this vehicle had the option of a closed top, would the inside be painted in Dunkelgrau or Elfenbein?