Actually for 55p I'd derust and regrind them as metal hand scrapers.
People are optimistic though, I was looking at planes on ebay and glanced at a Stanley #4 for £50, the following day I get a special offer through, get it for £40. Still seems optimistic given the condition:
https://www.ebay.co.uk/itm/195490031623
Sure I'm sure it would make a great tool but for the work involved it's probably £30 overpriced even with the discount.
The result of my search was spending £75 after postage for a Stanley #5 - that's a full price but I've bought from that particular seller before and visited him in his workshop. It's one of his refurbs and I'm happy to pay a premium for something I know will be ready to go out of the box.