My son has a tap in his garden that feeds a vertical fairly thick walled rubbery plastic pipe to a right angle connector. From there water was fed via buried rubbery pipe to 3 taps located at various quite long distances around the garden.
Last Winter in the frost, the rubber pipe to connector started leaking and produced a huge ice sculpture.
As a temporary bodge, I stuck a bar from a socket set in the end of the tube and held it there with a clip. It looked as though the inside of the connector was smooth and the rubbery pipe had been glued into place. There was no sign of anything looking like an olive.
I took some measurements and visited a couple of usually good merchants looking to buy some sort of connection arrangement, but only got talk like "that's imperial, haven't seen anything like that for years". They also said that any glue they sold would be useless because it would either not work or dissolve the plastic.
I've put some pics that might be visible at