I used to have to know about Copyright for my day job, but the law has changed somewhat in the 10 years or so since I retired and I have not kept up to date with developments. Any decent firm of Patent Attorneys should give you 30 mins free consultation and should be aware of the present situation.
Some general points which I think are still valid, (but don't rely on them!)
Registered Trade marks have be renewed every 10 years, and it is unlikely that trade marks from the 1950's would have been renewed.
Copyright may or may not still exist in the 1950's packaging.
The term of any copyright existing in the artwork would in the first instance be computed from the death of he author. I doubt that the original author's identity could be established, in which case the commencement date would run from the date of first publication.
Before European law got involved, the 50 year term for anonymous works would have expired by now, so there would be no existing copyright to infringe. However, copyright term has been progressively extended during the past couple of decades, resulting in the restoration of certain types of lapsed copyright. It's all very confusing, and dates are important to know what law applies.
The term of copyright for anonymous works used to be 50 years, but as a consequence of European harmonisation it is now I think 70 years.
The date of first publication will determine which law applies. If it was before 1956, then the 1911 Act applies. If before 1989, then it is the 1956 Act.
I really can't see a large company bothering with a museum that is only making one or two replicas for an exhibit. As noted.by others, to be sure you would need to contact the successors in title to Ever Ready and explain what you want to do. When I was with GEC, they were happy for third parties to reproduce their old stuff as long as acknowledgement was given. Someone was actually given permission to make and sell reproductions of one of their old books on valves without having to pay any royalties.
It's a completely different story where large-scale reproductions of expensive vintage stuff is concerned. The following link dealing with reproductions of vintage jaguar cars in Sweden gives some idea of the complexity of copyright law that have been brought about by EC-initiated law amendments. But in that case the vintage design is commercially valuable, unlike repro radio batteries.
https://ipkitten.blogspot.com/2021/0...plica.html?m=1