There is a 5th ave in the local yard, but has the bolted on wire-esque wheelcovers...leading it to be a 15x5.5.
going to this site to look thru the models/years for rims:
http://www.originalwheels.com/
Helps to some extent, but is also
missleading.
Wheel Part Number: #1140
1978-1980 Dodge Aspen
Size: 15" x 4", 5 Lug, 4.5" Bolt Pattern
Finish: Painted
Description: Used Factory Original Compact Spare Rim
Condition: Like-New
Wheel Part Number: #1140
1982-1989 Chrysler Fifth Avenue
Size: 15" x 4", 5 Lug, 4.5" Bolt Pattern
Finish: Painted
Description: Used Factory Original Compact Spare Rim RWD
Condition: Like-New