Thanks Charlie, so we now have the four Swedish ROM versions for the QL!
Last night, I was contacted by Pär Högberg who saw my posting about the Swedish ROMs on the QL group on Facebook. He said he also had a QL with MGB ROM and kindly sent me a photo of a different MGB setup:
Beckman_MGB_rom2.jpg
This also seems to use the original Sinclair MG ROM for the first 32K (just to the left of the carrier board), with a 27128 EPROM on the carrier board for the other 16K, with some changes to the code in the top 2 or 3 KB of that upper 16K, mainly changes to the message languages and keyboard table for the Swedish keyboard layout I think (after only a quick glance). The ROM version in his QL is also MGB/1Y13. Presumably the Swedish importer of the QLs just made their own temporary ROMs to adapt existing QLs for the Swedish market.
I gave Pär a link to the Forum, so he may join us in the coming days.