Technician reported a lockable latch that was installed on a B737 engine cowling was removed and replaced by a non lockable cowling latch when they were out on leave and was not documented correctly.

Narrative

Note: I was off work from DATE till DATE (work related injury). Shortly after returning to my work cell at which I have been working since Date; I noticed 2 RH fan cowls in our Serviceable Queue without Lockable Latches even though the P/N and documents called for it. I brought this to the attention of my supervisor and MPA (Maintenance Planning Analyst). I recommended the cowls be made unserviceable and paperwork packages be made so I could replace the regular latches with the Lockable ones as this was a safety item and when an A/C orders this P/N they expect to have them in place. The documents clearly state [this procedure] mandates both Lockable Latch and 30 hole Strake be installed in order to be serviceable. The reason I am singling out Cowl SN XXXXXXX is because on DATE2 this year after looking up repair history on XXXXXXX of which there are 5 pages ; on page 5 it clearly shows in I made a Lead request to put on the Lockable Latch after consulting with my lead and engineering. I installed it and I signed it off. I also listed the 3 parts I installed under Serviced Items in [maintenance tracking program]. In closing I need to make it clear; I know I put the Lockable Latch on; but upon my return to work I found a regular latch was in its place.