The Catalina Chronicles page (
Chronicles Volume I ) has the following version of the Russian purchases...It seems Guba (which went to Russia) and Guba II(which went to Britain) had Twin Wasp engines but the 3 US built Model 28s for Russia did have Wright Cyclones (one a/c delivered complete, 2 in parts as production start-up examples). The Russians apparently only built 27 'GSTs' with their license originally fitting the M-87 a 14 cylinder 2-row engine which was later replaced with M-62 9 cylinder (Cyclone based engine).Apparently one GST was flown to Cyprus by a Russian sailor (defecting? lost?) in November 1941 where it was acquired by the RAF as HK850 but never used, wrecked in a gale in Egypt February 1943. I suspect no photos exist of Guba II as G-AGBJ with BOAC. Russia was additionally supplied with Lend-Lease Catalinas