DL380 Gen 9 processor serial number

[Server44]

I'm trying to fill in a form for the free cashback offer that HPE are running. On the form it says 'Serial number' next to the processor kit I ordered (which was installed by the reseller). Luckily I still have the processor here and can access the unit, but pulling the lid off reveals 3 stickers on the 2nd processor heatsink, none of which say 'S/N' or similar. I can see a holographic sticker with 

• Security ID and a 7 digit code
• CT: and a 14 digit code
• PN: and a 6 digit code followed by -001

Otherwise there is a white sticker with 'Replace with spare', PROC E5-2620v3 85W and a number in brackets [762xxx-001]

There is another white one but this is for the heatsink itself.

Any ideas which one is the processor serial number (if any)?