i am a big fan of old bikes
as well as triples and bar end shifters
however
there are some real advantages to some modern parts
the advantage of a new set of hubs is not that you can fit 10 or 11 cogs on them
but that they have freeehubs instead of freewheels
and freehubs have support at both ends of the axle while freewheels have support at one end and in the middle
the difference in axle life is significant
especially if you are considering going to 7 speeds which would likely require respacing and having an even longer unsupported axle on the drive side
also regarding brifters
yes they really are that good that for most people there is no other real option
the ergonomics is far superior to bar end shifters and in a whole 'nother class compared to down tube
however they are much harder (or impossible) to service
and there is no option to switch to friction shifting
but almost all brifters last for years without any service
and indexed shifting is simple as pie to set up
only on a long tour would you be in a position to not be able to bring the shifting back to perfect before the next ride