The recipe yield is:
9 Half pints
Remove and discard pits from plums (do not peel). Chop plums into 1/2" pieces. Combine chopped plums, orange rind and orange juice in a large Dutch oven. Stir in powdered fruit pectin. Bring mixture to a rolling boil, stirring constantly. Stir in sugar. Return to a rolling boil; boil 1 minute, stirring constantly. Remove from heat; skim off foam. Stir 5 minutes. Stir in walnuts. Quickly spoon hot mixture into hot sterilized jars, leaving 1/4" headspace. Remove air bubbles; wipe jar rims. Cover at once with metal lids, and screw on bands. Process in boiling-water bath for 15 minutes. From Deb Williams in _Pot Luck_ by The Village Green/Temple, NH. In _America's Best Recipes: A 1989 Hometown Collection_. Birmingham, AL: Oxmoor House Inc., 1989. Pg. 280. ISBN 0-8487-0765-6. Electronic format by Cathy Harned.
Canning; Fruits; Harned 1994; Jam/Jelly; Nuts