Scotrail class 158's with 1st class section

[Barry J]

Having recently returned to living in Scotland, i've noticed that some, but not all Scotrail class 158 units have had a 1st class section re-created.

 

I recall that when 158's were introduced to Scotrail Express services in 1990, all units had a first class section. This was subsequently downgraded when the units were refurbished by National Express after being cascaded to Bathgate/Dunblane/Fife locals by the arrival of the 170 Turbostars.

 

Does anyone have any further information on this?

When did First Scotrail re-introduce the 1st class seating?

Which units have 1st class seating?

Are they intended for specific routes? They appear to be allocated to Haymarket & Inverness depots?

 

Any help much appreciated.