The shoes that 18 is wearing I’ve seen before they were a type of slip on shoes intended for outdoors. The thick soles gives a clue.

15 maybe wearing slippers, feet problems?

If 11 was born in about 1910, he looks to be in his 60-70 so the photo is about 1970-80. I think nearer to 1980 or maybe 1990.

No 17 is the odd one out, white socks and the jacket maybe white linen. Very few men wore those jackets and socks and he is younger than the rest. An outgoing type of person ?

I think 17 is the boss or senior management of a company and the others are retired staff. Could he be the President of a club and the others the older members. It’s that type of photo.

Where did 11 work and his clubs etc. ?

Allan C.