Jackets--North of St.Andrews sale

[auld argonian]

Okay...not to belabor the point, but if your chest actually measures 41 and a 40 is too snug and while a 42 fits the shoulders always seem to look a little too "Clark Kent-y" (for those who remember the old Superman TV series from the fifties)...where would that put me?

Best

AA

[Nanook]

Okay...not to belabor the point, but if your chest actually measures 41 and a 40 is too snug

If its "too snug". Really depends upon the tailor, resp. designer.

and while a 42 fits the shoulders always seem to look a little too "Clark Kent-y" (for those who remember the old Superman TV series from the fifties)...where would that put me?

Go visit a good tailor. Get the 42 and have the tailor pull it in. Its not much work (so should not be too expensive) to pull in it for a perfect fit.
If you were, however, serious with the "Clark Kent" I'd gather that you are short and probably in want of a bit lighter a jacket with less padding. Find a good men's shop with a good tailor and let the tailor help you work out your fit. Finding a good tailor, I do realize, is like finding a needle in a haystack but you will be apt to find them at some of the better shops selling not just brands like Oxxford, Regent, Brioni or Kiton but also Chester Barrie (not quite the stuff of 'ol which was clearly of the first league but I hear not bad either), Windsor, Canali, Ermenegildo Zegna, and a host of other good makers that don't glue their suits together. Shops with relatively expensive ready-to-wear suits (in the beyond $1000 USD class) tend to have call to find some good tailors to keep in business as their customers don't want to spend 1000s of dollars to look like "schleps".