There was another 142 upgraded with a dot matrix screen before these MerseyRail ones. Can't remember the number but it was in provincial blue which puts it early to mid 90s
142081 received dot matrix external blinds in the 1990’s by either RRNE or Northern Spirit (can’t remember the exact date) but it was a different system to the MPTE units. It lost them when transferred to Wales.
142051-058 along with the aforementioned 150/2’s, 507 & 508’s received the same Regional Railways MPTE livery in the early 90’s (yellow/white with black and grey stripes). The 142’s were ‘refurbished’ after privatisation arrived (well I’m 99% certain of that) and at this time 142041-049 were also done but with an FNW take on the livery omitting the black stripe. 051-058 also received this livery either during or after refurbishment. The additional 142’s replaced the 150’s which went into standard FNW blue/gold livery.
As mentioned, when Northern took on extra 158’s circa 2006 Merseytravel initially paid for the lease on some units to allow 158’s to replace 156’s and transfer them from Neville Hill to Newton Heath then eventually Allerton to take over local services in their area.
When Northern started their 142 refresh and relivery the MPTE 142’s were given the standard livery and blue seat covers and were treated as part of the core fleet although they often escaped to other areas long before this.
When Arriva ran Merseyrail Electrics (Arriva Trains Merseyside) they started to relivery the electrics into a similar if not identical livery to the 142’s omitting the black stripe but I don’t know if all units were altered prior to the full refurbishment was done (once Serco/Ned took over) and the units went into the original Yellow/Silver livery.
Incidentally 150213 didn’t stay in MPTE livery long as it was fairly quickly transferred to Norwich and given standard RR livery.