Finished entering my July 2004 #Interrail on https://viaduct.world . This trip* I did with my son who was 13 at the time.
Unlike my other Interrail trips, for this one we used a flight for one leg: We started by flying from Helsinki to the Köln-Bonn Airport. When going back home we did use surface transport, though.
Some of the train lines we used in France no longer have passenger traffic, so I was not able to enter all journeys* accurately. Meaning, the line between Clermont-Ferrand and Ussel with a branch to Mont-Dore. But I think viaduct.world allows you to enter a journey as a sequence of geographic points instead of a sequence of stations, so maybe I'll do that if I feel anal-retentive enough. (Haha, you can bet I now take it as a challenge and will do it.)
There might be other inaccuracies, too. For instance, it might be that in Sweden the København–Stockholm train back then ran via Nyköping and not via Katrineholm and Flen. Will have to check my Cook's for June 2004, to see if it has information about that. And yes, I do want to get such details as correct as possible.
We did spend lots of nights at hotels but it is fun how I almost don't remember anything about those hotels at all. For instance, I was a bit surprised to notice that we spent several nights in Paris, but I can't recall where.
Some interesting things we visited during the trip were the Royal International Air Tattoo at RAF Fairford, the National Museum of Computing in Bletchley Park, and Aigulle du Midi in Chamonix.
*) Here I use the Interrail terminology where a "trip" consists of a sequence of "journeys". Sadly, viaduct.world uses the opposite terminology.
@viaduct_world