Started out replacing voltage regulator (back of alternator) due to dim "oxy""alt" lights.Could crank the engine over but it would not fire.

Replaced alternator as 1 of the tracks that the brushes ride in was badly worn,and the other track was going that way.
Still the same problem.Charged the battery over night.
No joy.

Took high tension lead off distributor,held to eng,turned the key,eng turns but NO SPARK.

No spark means no secondary voltage,therefore no primary voltage (also don't have a meter).
My deduction is I have the dreaded ignition switch problem.

How does my deduction sound?
Any other suggestions?

Thanks
Gerry