well it's 15 - 91. The spool pin is missing .. that one looks clean, it about twice of what the going price is,,,
I have one as nice as that ,, it is a good machine, yet I don't like it.... because of the front tension mount and where they placed the presser foot lever it's ( for me ) a PITA to use, but I'm male and have large hands..
if you want a old singer look for a late model 66 these are fool proof if something happens to the motor you can get one anywhere ,, that 15 _ 91 eat a motor and it will cost more for a new than another machine would cost ..
if it were 40 to 60 $ then yes but at 150 he should save it to make bags to hold all his gold..