I can help with this as I researched the Bulgarian CV-33 for a model subject some years back (nice camouflage scheme). The MG mounting can be seen fairly clearly in the photo below (from the internet) and in photos of Austrian CV-33's with the same armament, I believe. I will e-mail you a few of the Austrian photos.
The MG tripod mount on the rear engine deck is a bit harder as few photos show it clearly. However, there is one in the Bulgarian-language book on Bulgarian AFVs 1935-45 - published a few years ago now. I will scan this in and send you a copy as well, but it will be tomorrow. It looked to me that the mount was secured to a plate attached to the engine deck between the two main hatches.
If you are modelling this subject, remember that the Bulgarians were one of the first export customers for the CV-33 and the tankettes they received were a very early version: this had a fair number of detail differences with the main production model.