David C tells me the seals which sit around the spark plug tubes, under the rocker cover, are not available.
which certainly doesnt stop oil leaking out!
anyway, i have a solution which others may find useful.
*i found that Bunnings sells a variety of EPDM products ie the same thing O rings are made from
*i used 9mm spongy EPDM tube, cut and glued into a circle with super glue
*this works with the non spongy EPDM as well, for making O rings of any size.
*i used these O rings instead of the worn out spark plug tube seals and it appears to be a/ completely successful and b/ very cheap.