Don't crash in the meantime as the insurance company would probably declare your aircraft to have been unairworthy at the time you took off and as such your C of A would be invalid.
Technically they would be correct.
You have a loose article in your tank which you are aware off.
It has the potential however unlikely to block the feed from the tank.
It might decide to wrap itself round the contents sender giving a false fuel reading, again highly unlikely.
For all you know there could already be something partially blocking the tank outlet and the chain could be enough to block it completely, again unlikely.
The aircraft is not airworthy and you fly it at your risk, not your insurance companies.
I would probably have made the same decision you did, to fly it back to base, but I would not continue to fly in that condition. Its tempting fate.