Replying to myself to add two further things which I should have mentioned before. Firstly I looked at the photos and that instrument is on gut. You can see it clearly here[1]. So you may have found it interesting idk but you can ignore everything I said about setup.

Secondly one thing that makes this instrument so special is that as rare and precious as original Amati and Stradivarius violins are, original cellos and basses are rarer. There are two reasons for this:

1) Because there are fewer cellos and basses in the orchestra than there are violins and violas, and fewer cello concertos etc than violin concertos for high-end virtuosos to perform, the elite makers made far fewer of these instruments originally. That goes double for an instrument like this that was literally made for a king. All of these instruments have a distinguished history but that's on another level.

2) Secondly, it's much easier for a large instrument to be damaged. Let alone just the day to day knocks etc that happen when you have a massive instrument cluttering up your house, given the history of wars etc in Europe since the 16th century it's practically a miracle that any of these instruments survived intact.

If you're interested in historical instruments, the Horniman museum in London has a great collection. https://www.horniman.ac.uk/ also there are pretty cool collection in Brussels https://www.mim.be/en and Amsterdam https://flutealmanac.directory/listing/rijksmuseum-musical-i...

[1] https://emuseum.nmmusd.org/internal/media/dispatcher/86655/f...