Here are just some thoughts and speculations:
1) Why would Shelby American want a mechanics lien against a wrecked car? Wouldn't a mechanics lien normally be for a car that a shop had done work on, but failed to collect payment on? It seems unlikely they did any work that they wanted to charge back to the owner of a wreck, right? Could it be the car was sitting around the shop from November of 1963 through April of 1964 and Shelby American wanted to simply get the car out of the shop because it was taking up space for months and the owner (whoever that was) simply did not bother to come to pick up the wreck? Unlike a wrecked Shelby team car that Shelby American owned and could simply cut up and throw in the dumpster, I am guessing that a car belonging to someone else would require a lien to get the car's title so that they could dispose of the car.
2) The owner of the car as of April 4, 1964 had paid it off in August of 1963.
2) We don't know whether Shelby American ever got the mechanics lien.
3) The wreck was intact in pictures from 1967, so obviously Shelby did not cut up the wreck and throw it in their dumpster to get rid of it.
4) If Shelby American never got the lien, is it possible that they eventually got a hold of the owner (whover the owner was) to pick up the car?
5) If Shelby American eventually got the lien and considering the wreck still existed, were they trying to sell the wreck to someone? Or sell it to a junk yard?
6) Who is Phil Curry? Maybe he could have been part of a car tags business involved in getting a title to the car in the case the lien came through? Maybe he was interested in buying the wreck for parts if the lien came though?
7) What is at Phil Curry's address? It does not look like a residence. You can lease the office building at that address now.
https://www.loopnet.com/property/514...37-5544014010/
8) The 1964 and 1967 registrations show a license number (which I assume is a license plate number): JJB 499
9) Well in this historical picture, there is no license plate.
10) Even if the car had a license plate, maybe it would be removed from the car to save weight during racing.
11) The registrations from 1964 and 1967 just indicate the year that the car was sold, 1963. Presumably that is the year that the car was first sold.
12) Let's say that you are Ann Abidin and you purchased the car in 1963, and the car was wrecked in 1963 and you have a valid title for the car you purchased in 1963. Why would Ann pay to register the car wreck in 1964? It is not like she was planning on driving it, right? Why register the wreck in 1964, if you have the 1963 title showing you paid for it in full in August of 1963? Couldn't you just sell the car with the 1963 title and 1963 registration without renewing the registration for 1964?
13) In my experience in Pennsylvania (which is not the same as 1964 California), my family was able to sell my aunt's old Mustang that had been parked in the garage and last registered in 1981 a few years ago using the title from the 1960s. We did not have to get a current year registration to sell the car.
14) So getting back to Ann Abidin getting a registration in 1964 for a car wrecked in 1963, why do that?
Wild speculation here: Is it possible that Ann got her first title and registration for CSX2049 in 1964, after she purchased the wreck from Shelby American after Shelby American finally got a mechanics lien on the car?
Mundane speculation here: Ann was the owner of the car and paid it off in 1963; Shelby American never got the mechanics lien; Shelby American eventually got a hold of Ann, and she eventually picked up the wreck from Shelby American; for some unknow reason she registered the undrivable wreck in 1964, but apparently wised up on wasting money on unnecessary registration fees and did not bother to register it again in 1965, 1966 or 1967.