I have received and exchanged correspondence with Dan Schorr, whose name many here will recognize from the late, lamented "Northern Wars" web site. Dan is someone whom I respect a great deal as a researcher, an historian and an author, and someone whom I'm proud to number among my acquaintances. Dan also has, in his personal possession, copies of Belaubre, Fouré, Charrie and Claus-Peter Goldberg as published by Wagner.
Dan has pointed out to me that there is some confusion, either in my understanding of Fouré or his writing, or in Pat's translation thereof. The relevant passage on the regiment in question and it's flags should be read as follows:
"Foure, which I believe you have, only discusses the colors from 1633-1679. I believe you are confusing Foure's statement, "It fought subsequently against us, notably at Neerwinden and at Denain where it left us several trophies (see Belaubre; Les Triomphes de Louis XIV No. 42 & 91)" with what follows which is a description of Hebron's colors 1633-1679, and not of those in Belaubre. The regiment's colors in English service during the Nine Years War and War of Spanish Succession were totally different from those described by Charrie and Foure."
Now, what does this mean to this discussion and to Nick's quandary? Dan has brought to light the fact that there is yet a third known (or at least attributed, set of flags for this regiment; these being the ones actually illustrated and cited in Belaubre's "Triomphes" and also in the Wagner/Goldberg set of plates (the two sources being identical).
I do not have permission to reproduce these flags here, as the material is subject to current copyright. I can, however, describe it to the best of my ability:
Field of blue for regimental, white for Colonel's, NO saltire or cross, the Regimental motto (NEMO ME IMPUNE LACESSIT), in Latin, in a circle almost to the edge, within that circle, ciphers (unknown to me) in eight positions, in the center a single thistle with a royal crown above, in the upper corner at the staff, what appear to be the arms of England in a shield, with Scotland centered. All lettering and devices (except the arms?) in gold on solid background of blue for battalion and white for Colonel.
EDIT: The flags pictured in Ray's photos above, particularly the 1st Battalion, are exactly what are illustrated by Belaubre and Goldberg/Wagner and referenced by Dan. Thank you Ray!
So, the progression, using the sources cited, would appear to be as follows:
Fouré/Condray's first example - Service from 1638 - yellow saltire on blue with Gustavus' intials.
Fouré/Condray's second example - Service under France during the Franco-Dutch War, yellow saltire on blue with border of fleur-de-lis and the Bourbon arms, used until 1679 and appropriate for the former Copplestone figures produced by Nick.
Belaubre and Golberg/Wagner - Solid blue and solid white with devices and motto described in gold, attributed to the Nine Years War and captured by the French at Neerwinden in 1693.
Charrie and others - White saltire on blue as described in many sources for Regiment Douglas, Orkney and as the Royal Scots, appropriate for some point in the WSS.
Once again, gamers will do what gamers will do, including probably using Nick's figures for either earlier or later periods. However, until we have a "wayback machine" equipped with camera's, the sources cited are probably as conclusive as we will get for the present. With all due respect to articles by Barry or anyone else, and secondary sources like Osprey's; Belaubre, Charrie, Fouré and C-P Goldberg (published by Siegbert Wagner) are considered the "ne plus ultra" of sources by students of vexillologie. My thanks to Dan Schorr for the clarification of my earlier statements and for sharing the additional sources with me. And, my thanks to Ray for providing the photos of his units.