Most Euston to Holyhead services are worked by HSTs or Inter-City 125s from September 1991 to May 2004.

A normal scene at Bangor as 43121 calls with 1A49 09:26 Holyhead - London
on 11 February 2004

43094 draws into Belmont Tunnel with the 1D87 08:40 London - Holyhead on
11 February 2004

A snowy scene as 43084 County of Derbyshire arrives with the 1D87
08:40 London - Holyhead on 27 February 2004

43123 arrives with the 1A77 13:41 Holyhead - London Euston on 7 May

Some power cars had Virgin removed before the end such as 43098 seen
leaving on 7 May

I rode the 1A49 09:26 Holyhead - London from Bangor to Chester on 11 May.
The last one was 22nd May but I was on holiday.