Given the last part — in ROT13: kanwn → xnaja — maybe it’s "kanwn" intended as “kanown” (could be “known” misspelled) — so perhaps the original encoding is reversing words:
But if it’s : thmyl → guzly tryf → gels tabt → gong kanwn → xnaja g2410 → t2410 thmyl tryf tabt kanwn g2410
But try on “thmyl tryf tabt kanwn”: guzly gels gong xnaja — still nonsense. Given the last part — in ROT13: kanwn
So maybe the whole phrase decodes to something about — “thmyl tryf tabt kanwn” could be “the walls of Jericho” encoded. maybe it’s a (G=4th letter
Given “g2410” is the key, maybe it’s a (G=4th letter, shift 24 = shift -2):
thmyl → lymht tryf → fyrt tabt → tbat kanwn → nwnak g2410 → 0142g
Given the constraints, my best guess is: It’s a puzzle where “g2410” indicates ; “kanwn” could be “known” (if ciphered), and “tabt” maybe “that”.