going cheap – only one owner

There are many things that I have never actually owned. A yacht, a camel, a pair of roller skates, a not butt-ugly couch, for example, are a few things that spring immediately to mind.
There are also many things that, while I have never owned them, I’ve always had access to them. This would include the particular case of my (used loosely) recently defunct, clock radio. It, in fact, is owned by my friend Tony. It was borrowed by me one day in 1998 and has remained with me ever since – a faithful companion indeed.
I’d estimate, and you may correct me if I’m wrong Tony, that it’s probably about twenty years old. And it’s showing it’s age. The gleaming exterior retains its attractive wood grain finish with nary a scratch, the “electronic digital” display still gleams a hazy blue into the night, and the alarm is good and rousing. Bravo General Electric – it’s made of sturdy stuff. Like a brick.
But something is wrong with the internal mechanism – it turns the radio on at random times throughout the day and night. Even when the button is in the ‘off’ position. It’s a trifle annoying.
And I haven’t been able to set the alarm for a number of years – employing a simple – yet effective – alternative which saw a combination system (utilising the ‘radio’ aspect of ye olde clock radio together with the ‘alarm setting’ features of my travelling “talking” alarm) instituted. Bulky, granted. But it worked.
The random radio selection has done me in, however. And a new clock radio has been purchased this weekend past. It’s silver (there was no wood grain). It’s small (an all in one working unit!) And it works a treat.
Is it rude to return the superceded clock radio to its actual owner? How long does a ‘borrow’ last?