I remember seeing this plane (and/or others of its type) flying during airshows, and I think I've even seen it depart for or arrive from its former maritime patrol missions.
The engines seemed to have some trouble starting, but they did eventually all get up to speed. Engine #1 in particular really didn't want to get out of bed, but the crew persisted and eventually it ran on its own power, although it seemed then to run significantly faster than the others before the cockpit crew did something and brought it back to a similar speed as the others. One of the volunteers keeping this thing alive mentioned something about "over-revving", so I hope the engine didn't take any damage from this run. He also confirmed my suspicion that the engines weren't doing so well, and explained that that was why they cut the engine run short. (I was at a similar engine run in 2014, which seemed to last much longer than the 10 minutes here.)
I hope this wasn't Pelican 22's last engine run.