Hey Glen,
Have a close look at the one your looking to buy, I’m thinking it may be something simple like different plug.
The one I see on eBay has a red button, probably hazard lights, does yours have that.
The switch on the YouTube is for a 70 Mustang and he said it’s for heaps of 70 ford cars, it doesn’t have the red Hazard switch.
I’d check other 70 model Ford switches, drop off Mustang in the description.
This one says.
This is a reproduction Ford and Mercury column mounted ignition switch for early 1970s models. This is an OEM quality service part. These are not a direct plug in for all applications. On some models the wiring is not long enough and will need to be spliced to a longer length by a qualified automotive electrician. Free shipping. Worldwide shipping available.
Another problem could be the plunger length, easy fix!
https://www.ebay.com.au/itm/300877860816I know it’s a lot of work but I’d respray your switch with something good to see if you can get something permanent.
Cheers Phil.