Inside a Mountain Breeze Ion Probe ioniser.04:33

From the construction I’d say this is probably one of the earliest Mountain Breeze ionisers, sine it’s clear that the PCB is hand etched and assembled. It also looks like it uses improvised housing components to give a neat finished appearance.
The unit would have been quite time consuming to build, since it is very much manually assembled and glued together.
Inside is the standard Mountain Breeze style voltage multiplier with the two 10 megohm output resistors and unusually a 10K input resistor too.
The neon indicator is brought down to the high voltage end which isn’t something I care for, since you are basically bringing wires from the low voltage end to the high voltage end. But there’s no sign of any corrosion associated with rogue corona inside. The indicator also uses a 180K resistor, which makes the later models with the failure prone 100K resistor look like a step backwards.
The single needle is in a standard turned pin socket on the front mounted in the centre of a plastic disk and with a small piece of PCB material at the back to allow it to be soldered in securely. This means that the needle can be replaced with a suitably thin one if desired. (or even a carbon fibre emitter).