I saw this tiny oscilloscope on eBay and had to buy it. It's so small for working with tubes. It only could have been better by having a tube rectifier instead of a selenium one.
I changed not working capacitors and had to solder in some resistors to cut away some voltage, because the main transformer is build for 220V AC, but the voltage has changed, and now we have 230V AC here in Italy.
I googled the relevant datasheets and linked them here, because I don't own them.