I have lived in Penrith/Kingswood all my life,that is a name from the past Lance Motors,If it did not have the names Frank and Derek I would of thought they were done by a Guy called Chris who started doing a simular style when he first started out but he became a tattooist.
I showed them to a mate of mine who has been doing murals since that time and he said he does not know who these guy's are,sorry I could not help you with anymore info.

Regards Tony.