[Q] won't boot normal or recovery [desperate]

Can someone help with a possible bricked an SGH-i337 4.3 UCUEMK2 build?
Got this on eBay & it "ran" great but this nagging voice kept saying, "it could be better on KitKat."
First let me say I’ve been rooting & flashing ROMs for years but this had me stumped.

After performing a successful "saferoot" I found RomManager couldn’t install ColckworkMod due to a locked bootloader.
I did install "Safestrap" but w/o fully understanding how to use it I may have killed it.
As of now I cannot boot into recovery, normal booting shows the Samsung logo with an unlocked padlock symbol.
Odin connects but with a locked bootloader I’m not sure if that will help since NAND write fails.

In download mode at the triangle screen this is what it reads:
PRODUCT NAME: SGH-I337
CURRENT BINARY: Samsung Official
SYSTEM STATUS: Custom
Knox Kernel Lock: 0x0
Knox Warrantee Void: 0x0
CSB-CONFIG-LSB: 0x30
WRITE PROTECTION: Enable
eMMC Burst Mode enabled

Any Devs out there that can prevent this from becoming an aquarium chew toy please help.
I’ve been trying to fix it for 2 weeks & about to give-up.
much thanks, Rick

Thanks jmjoyas

jmjoyas said:

You will be able to flash the full MK2 firmware using odin

Sent from my SAMSUNG-SGH-I337 using Tapatalk

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I've been looking for the modem/radio MD5 file but no luck so far. Even if I do find it I'm not sure if my locked bootloader will let me flash it.

MANY THANKS to jmjoyas & jd1639

after following your advice all is back to normal & backed up. now i need to study safestrap & push on to kitkat. thanks again guys.