Um, not sure if these will help in identifying the debris, but I came across PDFs of a few Lockheed L-188 Electra Field Service Digests (from 1958, '59 and '61), containing detailed descriptions, drawings, and photos of airframe, flight control system, power plant, etc. The originating Brazilian site is ad-infested and somewhat sporadic, so I've copied the files to:
https://www.dropbox.com/sh/7zhhl0jxu...tjxxnEeWa?dl=0
for easy download.
c