It would be interesting to look up the patent status. Others on HB seem to know a little about this, because I've seen some comments on other machines. If you're really interested, I suggest posting the question as a new thread.

Also, if you're getting into machine building I highly recommend testing an open-kettle lever machine like the Caravel or Gaggia Mini. In my opinion a well-designed and built open boiler, with a small pressurized steam-boiler included, would be the best thing to happen to espresso since 1950. Temperature control is everything in espresso, and it doesn't get any easier that open-boiler.

PC

Thanks PC for your encouragement and suggestions, your posts on your time with the PVE were influencing factors on my decision to purchase the Lusso.
I think I will probably begin with cosmetic modifications on my own machine and in the mean time begin a check list of things that can be done to bring this home use lever machine up to date, which is probably relatively easy but the biggest challenge would be to source the group assemblies since these are well tested in the field throughout the years and therefore no need for a complete redesign.

Missionhb posted this patent from 1963, probably has expired by now: