I second do not restore the bike leave it as is a little oil here and there and it would be good to go keep in the family even if you don’t have to have it it doesn’t take that much space and mabe your kids or there kids will want it It has been around 100 years don’t be the one to get rid of it
The hub is definitely Swedish and original to the bike and may be a useful dating tool.
There is another page on the site you found @NIC0, 'veterancykel.se' that mentions the hubs, followed by '36 -'39, which suggests a time range to me, but I don't speak any Swedish:
Looks like that seatpost and handlebar stem could be dropped by a few inches?
Could make it rideable, the frame doesn't look that tall, even with 28inch wheels, just a suggestion.
Along with everyone else above, I think that this requires no work other than regreasing/oiling where necessary then I would keep hold of it.
Personally I would use it whenever possible, it's a great family heirloom.!