the wheel - M5/9 11 -o- 11 55
M - Motor Wheel Corp.
5 - Plant #5 (CANADA)
9 - 1969
11 - November
11 - 11th
55 - 5.50" wide

IMO the wheel is from a '70 c-body

the tire - E78-15 Goodyear Polyglas Custom Power Cushion

'70 Chrysler STANDARD was H78-15s
'70 Dodge c-bodies STANDARD was G78-15s (H78-15s OPTIONAL)
'70 Plymouth c-bodies STANDARD was F78-15s (H78-15s OPTIONAL)

The twin stripe tires were used '70-71 (maybe '72?), but that tire is smaller than what the factory used for 15". Is the dealer stamp orange? Got a pic?

I'd guess the tire was replaced at some point, with the smaller & cheaper tire.

What's the DOT molded date code on the sidewall?