I have all the oficially released UK PAL carts (boxed) and the only ones which have the Spectravision name are China Syndrome, Cross Force, Nexar and Tapeworm. Gas Hog and Bumper Bash never made it to the stores over here - I got my copies from a friendly dealer who went to a trade show.
Most 3rd party titles have the 'compatible with Sears' legend on them.