No, it's not necessarily a plot hole. The show's history doesn't have to exactly match the show's 20th century background. (For example, Strife is still around in the 20th c. Hercverse, even though he died in the show.)

to ship seamen

[…] a morose middle-aged fellow who appeared at the Corry in a suit on weekday evenings but on Saturdays and Sundays was transformed by heavy boots, jeans and biking jacket, the ensemble looking just a trifle too much for him.

He, advancing close / Up to the lake, past all the rest, arose / In glorious object.