Tim, the marking dates are not relevant to the only operating period. They denote a period in time that Tamiya recognises as when the unit was active with the Stug Ausf B. It does not suggest the vehicle’s markings are relevant only to that single month. For example :
Wehrkreis responsible for formation: Wehrkreis XIII.
Date of Formation: 10 May 1941:
----- At the Old Camp at the Jüterbog Truppenübungsplatz, Wehrkreis III.
First Commanding Officer: Oberstleutnant Hesselbarth.
Replacement Units or Replacement & Training Units:
----- Sturmgeschütz-Ersatz [und Ausbildungs]-Abteilung 200.
22 Jun.1941… Attached to IV. Armeekorps, 17. Armee, Heeresgruppe Sud.
15 Jul.1941… Attached to XXXXIX. Gebirgs-Armeekorps, 17. Armee, Heeresgruppe Sud.
15 Sep.1941… Attached to LI. Armeekorps, 6. Armee, Heeresgruppe Sud.
22 Sep.1941… Attached to XXXXIII. Armeekorps, 2. Armee, Heeresgruppe Mitte.
2 Oct.1941… Attached to LIII. Armeekorps, 2. Armee, Heeresgruppe Mitte.
24 Dec.1941… Assigned to 2. Armee, Heeresgruppe Mitte.
4 Jun.1942… Attached to LV. Armeekorps, Armeegruppe “von Weichs”.
10 Aug.1942… Attached to XXXXVIII. Panzerkorps, 4. Panzerarmee, Heeresgruppe B.
24 Aug.1942… Attached to 24. Panzer-Division, XXXXVIII. Panzerkorps, 4. Panzerarmee, Heeresgruppe B.
17 Sep.1942… Assigned to 4. Panzerarmee, Heeresgruppe B.
1 Nov.1942… Attached to IV. Armeekorps, 4. Panzerarmee, Heeresgruppe B.
17 Nov.1942… Attached to IV. Armeekorps, 4. Panzerarmee, Heeresgruppe B.
Jan.1943… Unit shattered in the fighting around Stalingrad. The remnants of Stu.Gesch.Abt.243 were withdrawn from the front and reformed as a new unit.
2 Feb.1943… Unit attached to LVII. Panzerkorps.
16 Feb.1943… Unit attached to XXIX. Armeekorps.
4 Jul.1943… Assigned to the reformed 6. Armee, Heeresgruppe Sud.
*14 Feb.1944… Redesignated Sturmgeschütz-Brigade 243.
Tamiya’s date is Sept 1941, but the vehicle may have been delivered in May 1941 when the unit was formed. Unless the order of battle for the unit confirms that all Ausf B’s were destroyed or replaced By Oct 1941, it is not unreasonable to expect that some were still around for a while longer, especially considering an actual Ausf B was at least 4 months old in Sept 1941…
Then again, a ‘generic’ white wash finish with no other markings could be David’s intention.