Excuse my English as far as It is not my strong point and this is my first serious article in the language.
The D-32 gun is a variant of the D-30 designed for the self-propelled artillery piece Gvozdika 2S1-caliber 122 mm and a range of about 15 kilometers with the most common HE ammunition.
More specifically the D-32 descends from the D-30A, what we know thanks to the muzzle brake, very different from that of the first D-30s. Also this modified D-30A adds a fume extractor on the central part of the barrel resulting the D-32.
Obviously in Syria there are as many D-32s as Gvozdikas. According to the SIPRI Syria received between 290 and 400 Gvozdikas between 1982-1986.
The truth is that the Gvozdika is the most common self-propelled artillery piece in Syria, and as the 2S3 equips the best rate government units the 2S1 equips the regular army, because of this, as well as because of its high numbers a lot of 2S1s have been destroyed or captured by rebel groups.
Within destroyed it may happen that the vehicle as such is completely destroyed but the main gun has survived or performing some repairs may be re-tuned, this is perhaps why in Syria have appeared at least two images of D-32 towed guns.
That these guns are towed is clear sign that the vehicle that was carrying them was destroyed. Another possibility is that it is much easier to maintain a civilian vehicle that can tow the D-32 than maintain a Gvozdika that it is based on the old PT-76 chassis with far superior logistics and mechanical complexity.
On the issue of ammunition should not be any kind of problem and obviously towedD-32 would remain compatible with the same 122 mm ammunition fired by the D-30.
Finally the carriage on which is placed comes from an M-46 130 mm field gun, as can be seen by comparing the wheel rims of both pieces.
It is a very ingenious solution that has been done in Syria and certainly allows to fully exploit resources that otherwise would be wasted in a war of attrition as that of Syria.