Approx date for diesel lettering roadname change?

Micro-Trains has released Z Scale GP-9s in the "Guilford Rail System" paint scheme this month.

I'm far from an expert on Guilford but I think someone here might know this right off the top of their head.

I've been looking through the on-line photographs of these units-- numbers 52 and 54-- and I noted that prior to the roadname "Guilford Rail System" on the long hood, at least the 52 was previously lettered "Springfield Terminal" but in the same general scheme otherwise (gray, orange band, "Big G" on long hood).

I can narrow it down to "the 1990's" based on the online photos but does anyone have a more exact date or year for when the change from "Springfield Terminal" to "Guilford Rail System" occurred?

Thanks in advance...

They started lettering engines in the "Guilford Rail System" scheme in 1995.

Thanks! That's helpful!

umtrr-author wrote:Thanks! That's helpful!

guilford started in 1981 when timothy melon bought b&m maine central and springfeild terminal and kinda the d&h but they had to sell the d&h cause of like bank problems....idk hope that was helpful