Thank you all for the kind comments. I don't know how to quote several people at once, so I took notes and have a few answers to the questions:

For Tobus, Friday and Piperdbh: The pattern originally came from a 19th century tailor's manual reprint which a dance friend owned. I no longer have access to the book and can't remember the title. The pattern has been further altered with reference to a re-enactor friend's military waistcoat (US civil war) to get the up or down collar. The original collar did not go around the back but was sewn into the shoulder seam. So short answer is that there is not published pattern to which I could point you.

Harold: Yes, I have seen the bias good looking waistcoats on the bias posted here, however it was not an option in this case as it would have taken a wider piece of fabric than what was left. Madmacs: There was however just enough to get the sides without piecing provided it was not in the same width as the kilt's waist binding. The facings, collar and etc shared width with that. Also to repeat, note that the back is solid colour cotton fabric. That shows the limits of the remnant.

Piperdbh: Spending so much time in the 19th century, I am quite used to collars on my waistcoats. Glad however to bring such ideas to wider view. Hope you have success.

BuchananBiker: Sorry not to have been able to find your previous post and credit you personally in my original post. Thank you again for stimulating the thought processes. I will be ready now to join the Harley Owner's Group on their anual ride to the Highland Games in better style.