Default [Q] Vodafone UK to Europe RUU (stock)

So my phone was initatially VODAP001 which is Vodafone UK. I have unlocked bootloader, gained S-OFF and running ARHD 40.3 with latest official 3.62.401.1 firmware (1.55 hboot). I have the terrible issue with red/blue noise when taking photos in low light conditions (oh the irony of the 4MP and the ability to take low light photos being the HTC One's selling point) and I want to have it fixed. Thing is, I live in Cyprus and I can only send the phone to a service centre in Greece. This means I have to return it to stock.

Since I cannot find a Vodafone UK RUU, I thought I could change my CID to HTC__304 (already did) and run the RUU_M7_UL_JB_50_HTC_Europe_1.28.401.7_Radio_4A.13. 3231.27_10.31.1131.05_release_310878_signed. Considering that they may not ask for receipt and proof of where i bought the phone from, is this a wise thing to do? If yes, do I need to re-lock the bootloader before running the RUU?

In any case here is my getvar all

(bootloader) version: 0.5
(bootloader) version-bootloader: 1.55.0000
(bootloader) version-baseband: 4A.21.3263.04
(bootloader) version-cpld: None
(bootloader) version-microp: None
(bootloader) version-main: 3.62.401.1
(bootloader) version-misc: PVT SHIP S-OFF
(bootloader) serialno: xxxxxxxxxxxxxxxxx
(bootloader) imei: xxxxxxxxxxxxxxxxxx
(bootloader) meid: 00000000000000
(bootloader) product: m7_ul
(bootloader) platform: HBOOT-8064
(bootloader) modelid: PN0710000
(bootloader) cidnum: HTC__304
(bootloader) battery-status: good
(bootloader) battery-voltage: 4074mV
(bootloader) partition-layout: Generic
(bootloader) security: off
(bootloader) build-mode: SHIP
(bootloader) boot-mode: FASTBOOT
(bootloader) commitno-bootloader: dirty-bb768ae1
(bootloader) hbootpreupdate: 11
(bootloader) gencheckpt: 0