Buttons on a Doublet

[Phil]

Comments?

All I can see is that in the first picture (Mackenzie) the left-hand side of the jacket is completely covered by a fly-plaid. So it is not possible to see whether or not there are any buttons on that side.
Srewart Christie's take on a regulation doublet from the early 1950's and probably earlier appears to only have buttons on one side -


I am sure that there will have been many small variations from tailor to tailor and between clients' individual tastes.