Never seen ceramic fuses filled with compound. All sorts of other stuff but not fuses.
I visited the Electricity Museum in Funchal Madeira last week. Great little museum in the old power station. I was like a kid in a sweet shop with no signs saying 'no entry' or 'do not touch'. The old DC switchboard was brilliantly preserved. The even painted round the scorch marks on the ceiling where the breakers had arced. Lynn couldn't contain her excitement and had to go for a coffee and a nap. [emoji4]
Well, I can appreciate Lynn's enthusiasm... it must have quite a task to drag her away from that...

It's a no on the photos, nothing as hi-tech as those. I wish I'd kept a photo, they would make your museum pics look like next years' brochure

Each 'pot' was about the same size as a standard light bulb, but cylindrical, with a white and red button side-by-side on the end. As it tripped the red popped out and the white in. You depressed the red one to reset (after waiting 1/2 hrs or so for it to cool down) and if it locked, the white would pop out and you were good to go again.
If not wait another 1/2 hour...

None of that for me, the red stayed in and the pot just got hotter and hotter till it went with a bang, spewing this black tarry stuff, and catching fire.