Have you checked out the The National Museum of Computing (TNMoC) archive. Last time I was there they had a rather good magazine collection going back to the ea

Have you checked out the The National Museum of Computing (TNMoC) archive. Last time I was there they had a rather good magazine collection going back to the early 1980s. It may be worth a call. I see they have an (incomplete) online catalogue: https://www.tnmoc.org/library-archive https://www.tnmoc.org/library-archive