I think the second line says ARTIST COLL which presumably stands for artist collection. Can't read the last line, but as it has 5 figures it is not a year.
At
https://bergdala-glastekniska-museum.se/nedladdningar.html there are 6 files of the catalogue "Artist collection" from 1992, specially made for the 250th anniversary of Kosta glassworks. (scroll down a bit; they are in alphabetical order)
At this moment I haven't got the time to look through them all, but it might be that it is in there.
Just for the general knowledge (or do I mean gossip?): Bertil Vallien and Ulrica Hydman (later Hydman-Vallien) were married in 1963. (At that time they were both designing/making pottery) They were still married when she suddenly dropped dead in their home on the 21st of March 2018. She started designing glass in 1972. She was also a painter.
Bertil Vallien was born in 1938, and considering his age I do not think he is "the head" of anything anymore, even if he is still active.
And... while I am "at it": Kosta is a village with a very old glassworks, est 1742, called Kosta glasbruk. It is still in operation.
Boda is a different village, even if quite near to Kosta. The glassworks was shut down in 2003.
KostaBoda is a trademark, but at this moment I can't verify exactly when the trademark was created. (should have been in the '90ies, methinks?)
The trademark is still in use, even if a lot of the production is outsourced to various countries - at the top of my head I recall Slovenia, Czechia, Bulgaria, Turkey and India (from what is printed on their packages).
(The same goes for Orrefors (the trademark) - the glassworks was closed in 2013, production going on in Kosta plus sevaral other countries, among which one is Slovakia.)
The ownership, cross-ownership, bankrupcies and take-overs, trade-marking etc of the "modern" glassworks in "Kingdom of crystal" - for those of you that read Swedish,
https://www.glasriket.se/sv/glasrikets-historia is a good place to start. For some reason it was decided not to translate that page, so I guess
https://www.glasriket.se/en/The-Glassworks is the best the official website can offer to English-speakers. (You might want to try g**le translate to get an idea of the history?)
Kerstin from Bergdala, which is a neighbour village to Kosta.
(edit typo)