A contractor from Rockville, MD says:
June 6, 2015
The spring is 18.25 inches long .375 round. The spring appears to be ok but the truck is broken. the truck is .5 x .5 x 2.375
Paul from SWISCO responded:
June 9, 2015
Thanks for posting! If the spring is okay, you may be able to use our 15-104 friction shoe. Is this a match for your broken part?