Wow, BDC! That was
fast and pretty exact. Are you an ALCo fan?
The one that you have is the other TECSA ALCo loco, the 318.009 that, as you have stated, is an DL500-C. The 316.017 is an DL500-A. When it was purchased by RENFE (National Spanish RR's) in 1956, it came with an 244-G prime mover (instead of the 251-B one of the DL500-C). In 1972, due to lack of spare parts for the 244, it had the engine changed to a newer and more powerful 251-G3. Finally, in June 1994, it was sold to TECSA, a private rail maintenance contractor. The 318.009 was also sold to TECSA three months before, in March 1994.
The main differences (apart of prime mover) between the two "sister" locos are:
DL500-A: double headlight (in fore and aft. cabins); no MU plugs; one step in pilot; nose class. number board cleared.
DL500-C: single headlight (in both cabins); MU plugs; two steps in pilot
I took the pic just yesterday, in the international RR facilities of the Spain-France border, in Irún. I imagined that Woodie or another aussie member would "get" it first, because more than 100 of these DL500's were built in Australia under license.
I like a lot these nice locomotives. When the first one of the batch came to Spain in 1954, the railmen nicknamed it
"Marilyn" due to its origin -the USA-, its peculiar "swing" when idle, and its protruding nose (but they weren't thinking about the actress nose!!

)
ALCo publicited these export locos as "World Locomotives" (
locomotora mundial). Here is an March 1956 spanish ad: