Electrical solderless or soldered connectors
i have found in most cases that the loom is usually good, unwrapping a 50 year mopar loom you find the middle looks like it wut there yesturday and the inulsation on individual wires is rarley brittle. its the last 6 - 12 inches that has existed unwrapped or exposed under body or under hood, that is the problem
i have tended to do a lineman's spilce with heat shrink to add in a new length of the same colour and have used OEM style crimp on connectors with the kind of rubbery style boot that you slip onto the wire first when it is appropriate.
for modular plastic, ebay will find you a "50 different style" multi tool set for removing "Tanged" connectors that fit into modular plastic holders you will only ever use about 4 of them but for approx $7...
or make your own by grinding down hacksaw blades on a wheel or belt and inserting them into cork or nylon as a handle.
a wholesale swap of loom or even just connectors to a new modern type is a big job. keep in mind everything there, kinda worked fine for 20 30 40 years until somone messed with it, added in those horrible blue snap lock connectors or the car was left standing unused..thats the killer usually.
any car this age will have some corrosion/tranish/virdigris on the connectors... clean it off with a little brass brush and use a smear of vasaline/petroleum jelly when you re connect
or crimp on new connectors to all your new lengths of wire at the comfort of your desk, with appropriate boots on and then have a day of linemans splice and wrapping. doing sets of each boreing repetative action gets you pretty good pretty fast at each skill.
if you need to wrap the loom use original style cling tape with no adhesive.
but never unwrap all of your loom at once. you can make a right mess.
if you do unwrap you may well find that chrylser did the odd junction iteslf hidden out of sight, when one reel of yellow with black trace ran out, and they spliced on the start of the next.
good for another 50 years
Dave