One thing has been tripping some up is what the source is.
Run the set with NO signal, just snow. If the whole screen lights
its a source problem. If it still has bad width its the TV.
Best source is a VCR or early DVD & modulator. May not work perfect but
good enuf to fill the screen.
At that point you have to narrow it down to the stage level so as not to
waste time, $$, or risk making matters worse.
Multiple images may be normal. Later sets with coil hoz hold can
get it if turned too far. Tin whiskers in a pot can too.
73 Zeno
LFOD !