From March 1944 the "leichte Flakpanzer (light AA tank) mit 3.7 cm Flak 43 auf Pz Kw IV Ausf J", known as "Ostwind'; (East Wind), was produced by Deutsche Eisenwerke. As in the Whirlwind the crew was now housed in a strongly armoured (25mm all round) rotating turret. The combat weight with a seven-man crew and 416 rounds of ammunition was 25 tons. Forty of these vehicles were built. The Ostwind was also capable of engaging ground targets and served with the AA platoons of Panzer divisions until the end of the war. As with the other Flakpanzers this open-topped relatively tall vehicle was only an expedient.
On 18 August 1944, an order for 100 Ostwind (east wind) was placed, after successful trials had been held in July. Replacing the Wirbelwind, Ostwind I provided the Panzer troops with the more effective 3.7cm FlaK43. Both Ostwind I and the Möbelwagen were to be replaced by Kugelblitz, but because of delays, only two Kugelblitz were produced, and seven of the chassis were used to produce Ostwind I.
While the Wirbelwind was built upon unchanged Panzer IV repair chassis, the Ostwind was built upon a changed superstructure of the Panzer IV which was built especially for the Ostwind. For the Ostwind only factory fresh vehicles were used, except for the prototype.
A six-sided open-topped turret was mounted, in place of the normal turret, on converted Pz Kpfw IV chassis. The turret could be traversed 360° to bring fast, effective fire on air or ground targets. Issued to the Flugabwehrzug (AA platoons) of Panzer regiments in Panzer divisions.
Even Count von Seherr-Thoss, the designer of the Ostwind, doesn't know exactly how many Ostwind were produced (although it probably was in the range of about 40 vehicles). We do know that some test vehicles saw troop trials in September 1944, but by the end of that year the production facilities were being moved constantly to keep them one step ahead of the Allied advance.
Jentz (Panzer Tracts 12) refers to a 1st April 1945 report that six vehicles (completed March 1945), intended for Fla-Pz.Kp.z.b.V., were available for issue at Bielefld but does not say whether they were actually issued, let alone saw combat.
Terlisten (Nuts & Bolts 13) gives the figure as seven but is also unclear on which unit received them. He does mention the production facility moving to Teplitz-Schoenau in January 1945 and speculates that if they did see action, it is likely that they did so on the Ostfront in this area.
Seven Ostwind were produced in March 1945.
s. Pz abt. 507 had some Ostwinds in 1945. The only information I know so far is that sPzAbt. 507 received a few or at least one of them at the end of the war. But at that time they haven't been a sPzAbt. anymore, but were reorganized to a PzJgAbt, if I remember correctly. There is one photo taken at Nove Benatky, which probably shows one of them. Possibly at that time they might have been part of KG Milowice.
The Ostwind destroyed in Nove Beatky belonged to the Kgr. Milowitz indeed. This Kgr. was made up from the garrison of the Military area Milovice and trainees and instructors of a Panzerjaegerchule which was located there. Personal of sPzAbt 507 (redesignated into PzAbt 507) was among them too.