[sidney]

I have also checked the "sister" unit, the I./JG 71, in this respect. In the aforementioned reference Jagdfliegerverbände (JVE) der Deutschen Luftwaffe 1934-1945, Teil 1, pages 258 – 260, the authors dealt with Jagdgeschwader 71. I gleaned the following:

1. The formation of both Staffeln of JG 71 followed from the elements of I./JG 51 at Schleissheim, where both Staffeln were equipped with the Bf 109 D-l aircraft.
2. At the end of July followed the move of both Staffeln to Bad Aibling to I./JG 51, to which they were subordinated as well.
3. At Bad Aibling at that point in time there was an ongoing course (i.e., Lehrgang) for the reserve fighter pilots led by Maj. Kramer; thereby it was managed as a newly assembled Staffel, which was equipped with the Avia B534 aircraft taken over from the former Czech air force, which however were at once handed over (i.e., presumably to 1./JG 71?).
4. For the fliers training stood one with the Bf 109 D-1 aircraft equipped Staffel under Lt. Nagler; as far as it is known, this Staffel never received an official designation, and was mentioned in records only as Reservestaffel/JG 71.
5. On 26 August 1939 moved three Staffeln in the course of the general mobilization to Fürstenfeldbruck airbase, to undertake the fighter protection over München.
6. On 29 August 1939 the 1./JG 71 moved from Fürstenfeldbruck further to Böblingen.
7. The "I./JG 71" Staffeln strength report of 31 August 1939 gives 34 Bf 109 D-1

From the above, providing that both 1. and 2./JG 71 were initially equipped with the Bf 109 D-1 aircraft, it is hard for me to see the need for the obsolescent Avias to be handed to the 1./JG 71. Furthermore, it is perhaps strange that an officially formed Staffel (i.e., 1./JG 71) had to handle the Avia B534 aircraft, while at the same time an unofficial Staffel (i.e., Reservestaffel/JG 71) was equipped with the Bf 109 D-1 aircraft.

What also intrigues me is the series of photographs in the JVE der Deutschen Luftwaffe 1934-1945, Teil 2, II./Jagdgeschwader 52, pages 322 and 323, photos 381 – 384 featuring the Staffel’s Avia B534 aircraft with the 1./JG 71 (early) winged devil emblem and caption "... some pilots of 1./JG 71 at "readiness" at Bad Aibling in the beginning of September 1939..", while at that time they were already supposed to be based at Böblingen (i.e., from 29 August 1939), and definitely equipped with the Bf 109 D-1 aircraft, as per the above discussion.
-----------------
From the above discussion in these three posts, the possibilities, as I see them, are as follows:
1. Both I./JG 70 and I./JG 71 had Avia Lehrgang (course) associated with it, with a complement of the various models of the Avia B534 aircraft, or
2. Only I./JG 71 had the Avia B534 aircraft, or
3. Only I./JG 70 had the Avia B534 aircraft.

I understand that this might not be the most interesting topic to discuss, but nevertheless I hope that some experts might find the time to comment, and clarify the matter. Or otherwise, if they see no ambiguity in the quoted references, just simply state so.