The price may be up a bit because of the oyster black finish, which is pretty popular. However, since there is no indication that its chief user, Ringo Starr, ever had a 20, 12, 16 configuration, the value would be a little lower than it might be in a 20, 12, 14 or 22, 13, 16 configuration.
On the other hand, how many oyster black sets are likely to be found in Europe in any configuration? Given the rail mount, it does seem to have been a three piece kit from day one. The ply separation and shape issues are fairly common in my experience for Ludwigs of that era and not too big a deal. There does appear to be a Rogers muffler on the small tom based on the knob type and the flat plate with two bolts. From the inside though, it doesn't have Rogers components if that is the same muffler.
The crack looks to be the result of the floor tom leg taking a hit - maybe from the drum falling over - but probably from the drum being dropped on its side. Doesn't look too bad though.
I'm going to say that if you are only getting the bass, tom and floor tom, the price seems a bit high. However, I don't have a great sense of prices in Europe. In the US, it might bring $1000 to $1500 depending on the close-up details, but a buyer also has to be prepared to find some of the missing parts. I think there has been a 20, 13, 16 in oyster black recently either on eBay or Reverb for about $2250, but seems not to be selling at that price.
Good luck with your deliberations!
