Thank you for allowing me to join the forums! Google searches just keep spinning me around in circles.
Essentially, just looking to be properly educated as to what I own, and what else has been done incorrectly.
1955 Thunderbird, 292, 6V Pos Grnd, Fordomatic, 43K original miles.  

I'm the 3rd owner as of 3 months ago, and have been uncovering some 'unique' issues that were apparently performed by the previous owner's 'mechanic'.
My bird has a Mallory YC dual-point distributor, with (I'm guessing) a tach drive cable. 
I've already discovered that the rotor was incorrect (too large) so the contacts under the cap were filed down to compensate (!!!) She ran fine, until she got too warm, and then re-starting was a chore.
My question(s):
> Were the YC's ever installed at the factory or only as replacements (upgrades?) later on?
> My understanding is the 55's Tach was vacuum driven off the distributor, but there's only a cable going to my tach and no vacuum lines coming from the distributor.  
> Is it wise for me to tackle swapping it out to the stock-type 55 Tbird distributor, so I can convert to electronic ignition (Pertronix doesn't make a kit for the YC's)
Thanks in advance!