Don White answered the purpose of the Abteilung. Here's some history of the unit. On Jun.17.44, H.Gr.Mitte was ordered to send a cadre (one Komp.) of the Pz.Jg.Abt.383 to the Tr.Ub.Pl.Mielau in order to convert to Stu.Gesch. On Jun.28.1944, H.Gr.Mitte reported that the Stamm for the new Stu.Gesch.Abt.1383 was en-route to Mielau, but strangely, the unit did not arrive until Aug.3.1944. During this time, on Jul.10.44, the 1383 was ordered to be placed at the disposal to one of the forming 29.Welle Divisionen (541.-553.,558.-559.Gren.Div.). On Jul.16. it was ordered to form as the Stu.Gesch.Abt.1548 (548.Gren.Div.), but on Aug.16.44, it was renamed Stu.Gesch.Abt.1549. The unit was equipped with 10 Stu.Gesch.III that was sent to the unit on Aug.5.44, and 1 Berge.Pz.III sent to the unit on Aug.22.44. On Aug.17.1944 the Stu.Gesch.Abt.1549 (fr.1383) was sent to its parent Div. (549.V.Gren.Div.) on the E.Front. The Div. mainly fought with H.Gr.Nord. On Jan.15.1945, the 1549 reported having 6 Stu.Gesch.III (4 combat ready, and 2 in repair) plus 1 Berge T-34 as a recovery vehicle. However, the 549.V.Gren.Div. was quickly destroyed during the January '45, Soviet offensive, and on 1.Feb.1945, the 549.V.Gren.Div reporting no Stu.Gesch. on-hand. It is assumed that the Pz.Jg.Kp.1549 was completely destroyed at this time. During the month of Feb.'45, the 549.V.Gren.Div. was rebuilt using the ad-hoc Div.Denecke, but the Stu.Gesch.Abt. (Pz.Jg.Kp.) was not re-built.
I hope it helps