Injector seals

well thought I had a leaking injector ring today so got the diluted washing up liquid out and went to find which one it was. Non odd sounded like one. After a bit of head scratching noticed some bubbles forming right at the back of the engine tight up to the bulk head.Me thinks cylinder head gasket though no other evidence.Is my diagnosis correct ?

Dead common on number 4 cylinder on the 200 engine.
Look down the drivers side and you can see how many notches the gasket has, this denoted the correct thickness for the replacement

Lynall