Maybe I can't see for looking, but I can't find the "Find (on this page)" option on the toolbar. Could anyone point me in the right direction please?

go the very top right hand side of the screen, and you will find a small symbol for "search".
Beside this there is a drop down arrow. Left click on this, and you will get the "find" option.

Try pressing the ctrl and F keys together, that should bring up the Find box

Thank you, much appreciated