The case looks about the same as this one: https://www.chrono24.com.au/longine...35mm-spider-lugs---mens-watch--id35430106.htm
Guessing from the era it would be a Longines 23Z movement but they’re not my specialty, not hugely valuable but very good reliable watches and worth having serviced and wearing if it has a family connection.
Doubtful, my grandfather died in 1993 and I do not believe the watch has been out of a drawer since then and I also doubt very much he would have ever had the dial retouched in any way.
It was common practice for watchmakers to refinish or touch-up dials in the past as watches did not have very good water resistance so it was often done as a part of normal servicing, for watches of that era it’s extremely common and was probably done prior to the 1990’s