Here is what I got about the pre-war Grumman Gooses:
The BPM and NNGPM operated Grumman Goose aircraft before and after the war. The pre-war fleet consisted of PK-AER, PK-AES, PK-AKA, PK-AKB and PK-AKR. In addition the registrations PK-AKC and PK-AKD had been reserved for Grumman Goose aircraft but were not taken up. PK-AER entered service in July 1938 and was previously G-AFCH. It was written off at Sedani on 26 January 1942 although an alternative reference source quotes 26 December 1941 as the date it was destroyed by enemy action at LakeTondano. PK-AES was acquired on 20 June 1939 and was previously registered as VH-AAY. This aircraft was written off on 24 January 1942 at Koepang. The first PK-AKA was acquired in July 1939. It was leased to the KNILM in November 1941 and was eventually destroyed at Andir on 8 March 1942. PK-AKB, which was acquired in August 1939, was written off at Dobu on 2 February 1942. Finally, PK-AKR, which was previously registered as VH-AAZ was acquired in November 1937 and was later returned to VH-AAZ. There is also evidence of a Goose captured by the Japanese as Andir.
And here is PK_AES at Andir on 18 Nov 1938, 73 years + 1 day ago