Imperial spanners have little use except to people who work on vintage machinery or vintage cars/bikes.
There aren't a lot of us about these days as the cars, bikes and machines are becoming rarer (they rust and wear out faster than the tools) and the younger generations seem less likely to take up the interest.
I, like others, inherited most of what I need from my father.
If I were looking to buy, I'd watch ebay for the specific spanner or a set.
I would only buy a good example, and only a good name. They would have to be correctly described or they would never match the keywords in my saved searches. Terms like BSW, Whitworth, A/F (across flats), not just the size.
If they are chromed and not peeling, ring spanners or sets, name brand like britool, gordon, elora, and a few more, they may be of interest to someone.
Open end + non chromed or no name, I would give away or toss in the metal recycling at the tip. At a car boot sale, they might bring a few pence each and if you are lucky repay the cost of entry.
Anything that is visibly distorted (I can see at least one where the tips of an open spanner are flared out) I would assume to be made of poor steel and worthless. It may not be but as there are plenty to choose from, I wouldn't give it a second glance.
Steel has generally improved over the years so very old is not better. The quality of spanners peaked in perhaps the 80's or 90's. Nowadays there is less choice and most of the famous brands have declined through changes of ownership and cost cutting.
Financially it is best to accept the fact that most old tools have little or no value.
Many of us want to see the things our family leave behind be put to good use. It's a sad lesson to learn that generally people don't want them. Keep what is useful or sentimental, donate the rest to a local men's shed. There will be some older folk who will probably recognise anything of value and may take a table at a local steam fair to sell off the dozens of hammers they are given every year for 10p apiece.
