G-AGUP, c/n 6911, was ordered for the RAF (serial NR847) but not delivered due to the end of the war, eventually it was civilianised and sold, as new, to IOMAS on 20 December 1945, as their last aircraft acquisition. The fleet was integrated with BEA on 1 Feb 1947, and it ran on with them until 1952 when it was sold to Jersey Airlines. Having been in Ivory Coast, Africa, for a while it ended up in France where it was scrapped in the mid-1960s.
IOMAS disappeared into BEA, and two days before the merger, on 29 January 1947, the Chairman, Read, gave a party for the staff, a number of whom had served throughout the war, when they carried on the scheduled service, one of very few allowed to continue in wartime. Their main technical and engineering base was at Liverpool Speke. After the BEA acquisition the same staff, and to some extent aircraft, carried on. There was much opposition from companies and staff to the takeover, until the latter realised that BEA paid on a national pay scale, determined in London, which was well above what they had previously earned !
1946 was thus their only postwar summer season, for which they had three Rapides (Wikipedia incorrectly states four), plus they hired in additional aircraft at weekends. After the merger BEA put DC-3s on their main IOM flights, but a whole range of independents were allowed to run summer services from lesser points which BEA did not serve, and this included Blackpool, initially transferred with IOMAS but given up by BEA after 1948. Lancashire took over the route next summer, but had been doing charters on the route previously, and in fact the scheduled operators made considerable use of subchartered aircraft from independent companies to cover the high season summer operations.
Regarding the logo visible on G-AGUP, I can't say. It's not BEA's of the era, which looked like a key, with wings above and BEA below. IOMAS seems to have had multiple logos, one was a wing with a circled A through it, another is bars through a Manx three-legged crest. But this one seems different again.