Basic, Hamish Moore bought his first set of Scottish small pipes from Colin Ross. Colin had borrowed a set of SSP's from a museum and taken the bores and measurements etc and made a set. Since then he has brought the SSP's into modern day tuning so they can be played in with other instruments in sessions. (all subtle changes) Hamish and his brother have also made a few changes (Hamish is a tremendous player) but I believe Colin to be the more knowledgeable of the two.
Colin is semi-retired now but is always available for advice.
cheers eoin