Earth continuity on older domestic appliances?

I’ve recently completed the City and Guilds PAT testing course, and do volunteer work at a local charity, testing donated appliances to sell on. We had an old item of Class l equipment in recently (1970s), and when earth continuity was tested from earth pin to body there was a resistance of 0.23 ohms, over the limit of 0.1 + R, and therefore an apparent fail.

We’ve got some old manufacturer’s service manuals, I looked it up and was surprised to learn they stated a maximum resistance from earth pin to body of 1 ohm, much higher than the PAT test requirements and what EN 50106 specifies for new equipment, although this presumably conformed to BS 3456 when the appliance was built, as it has the old kite mark. A bit of Googling also revealed that Australia and New Zealand both allow a resistance of 1 ohm on their equivalent in-service testing.

So my questions: Is this higher resistance limit a hazard? When did the limit change from 1 ohm to 0.1 ohms + R? And would it be illegal to sell it on for domestic use? I’ve heard that it has to be safe, unmodified and just needs to conform to the standards that were applicable when it was manufactured.

Thanks for any help or advice you can give me!