Air Belgium, of course. OO-PLH, sometimes wore her own livery, sometimes that of America West. Sometimes she even flew for Air Belgium rather than subbing for somebody else.
I think Sabre and Peach Air were both post-1990. I'm not sure about Ambassador but I think G-BFVA and
VB were common factors here! Might have been BECG and CH. All Britannia cast-offs anyways.
What an incredibly successful aeroplane it was. Interesting that Britannia didn't go for the -300 (and -500) until much later, the Orion aircraft notwithstanding.