John W Welford (known to his friends as Jack and his co-pilots as John Willie) gained the soubriquet "Full Tanks" thanks to an apprehension about fog - perhaps acquired on Dakotas in an era when precision let-down aids in Scotland were few and far between. I have him to thank for one unplanned but very pleasant n/stop in Kirkwall.
One of the many anecdotes about him concerned a departure from Kirkwall to Aberdeen in haar conditions. The aeroplane then flew on to Renfrew and eventually to Jersey.
It was said that Kirkwall received a signal from Jersey asking whether they had a licence to export fuel to the Channel Islands.
The story about entertaining the passengers arose when the Viscount came on the scene. Captains were urged to use the new-fangled cabin address to ensure that passengers were "entertained"
Welford was reported to have emerged from his cabin-address free Dakota cockpit announcing, "Ladies & Gentlemen, my company has said you are to be entertained; entertained you shall be!"
However, my informant maintained that he was carrying a violin case from which he produced a penny whistle.
Given Welford's form, the ukulele version cannot be ruled out - but he was known to play the whistle.