I've got one of these kits - I've had it for years
Gunson | G4062 | Eezibleed Kit
It is quite amazing that it has lasted so long and has been used on so many cars with different master cylinder caps - it is very much DIY quality - not professional quality - but it is soldiering on today.
Here's more information about it
http://www.gunson.co.uk/items/pdf/Products/G4062_booklet.pdf
that you might be able to use to your advantage.
The biggest problem with the system is that you are meant to use pressure from a spare tyre as the pressure source. In principle this is all good though at 20PSI you need a nice big tyre to keep yourself going whilst bleeding a W123.
I've now hooked it up to my air compressor via a pressure regulator of course!