Did Bahco acquire Berg from Sandvik? Both the chisel & plier lines appear to have been part of Sandvik...
It looks like Bahco acquired both Berg and Jernbolaget, back in '59. Then Sandvik acquired Bahco in '92, so '92 would be the year that Sandvik got Berg.
Whether a chisel is Berg, Jernbolaget, or Sandvik ... I have to look for a manufacturer's mark to find out who made them. They all look nearly identical. My first ones were Sandviks. I just went out and looked at the two that came in a box of tools that came with my 1949 ShopSmith. I'd paid no attention to the maker and assumed they were Sandvik made. But no. Both are Jernbolaget chisels, and almost certainly from before Bahco's acquisition of Jernbolaget and Berg. They (and my Sandviks) look exactly like the tang chisels in the 1935 Berg advertisement. They both have remnants of their paper labels on the handles exactly like the paper labels shown in the 1948 Berg ad, except the labels have the Jernbolaget anchor logo and the name, Jernbolaget.
The quality is the same among all that I have. Incestuous? Just a bit. But Eskilstuna has been making tools for a few hundred years, so maybe we can write the resemblance off to a standard design adopted by Eskilstuna tool manufacturers.