I don't disagree. So many times we look at a Home and it's just another machine. We're talking about this one. It has interest.I'd be tempted to leave it as-is.
There should be a couple of rings around the carriage rod. A machine in the two minute mode should take one minute to travel that distance. The rpm of the mandrel is the same for two and four minute operation. The difference the engagement or speed of the feed screw. On a regular two minute Home the feed screw is part of the whole mandrel assembly and is fixed in place. A conversion kit for a Home or Triumph requires a whole different mandrel with a separate feed screw that is not permanently attached to the mandrel shaft. (Maybe someone else can explain this better than me!
Jerry