I'm up in Inverness this weekend.
So, for the record, the First Class seats are in coach A. They are numbered 1 & 2 (four seats around a table), 5 & 6 (airline), 7, 8 (four seats around a table), & 9 and 10 (four seats around a table), so a total of 14 seats altogether.
The refurbished 158s are smart - today, I travelled from Inverness to Aviemore on one of the few remaining unrefurbished ones, and there is a marked difference between the two. Not least that the refurbished one had heating (but was full of reservations) and the unrefurbished one was freezing cold (but empty).
My next trip to Scotland is at the beginning of May, so I am going to try and reserve some of the specified First Class seats on a trip to Kyle and back and see what happens!