The Technicolor TG800vac reports DISTRIB_TARGET='brcm63xx-tch/VANTY' which I understand refers to the MIPS cpu (BCM63168) as used in the TG789vac/TG799vac rather than the ARM cpu (BCM63138) as used in the TG800vac/DGA4130 (Ref).
The binary files and any specific hardware supported will not be compatible. Which files are compatible between these two installations?
config settings in text format and GUI source files in lua format (text).
The whole target 'brcm63xx-tch/VANTY' looks like something from Technicolor's proprietary repo, so I doubt that anything binary would be compatible. To my knowledge there has never been that target in normal Openwrt.
You should maybe look at the /proc/cpuinfo and clearly identify, which kind of processor you are running.
Example:
root@LEDE:~# cat /proc/cpuinfo
processor : 0
model name : ARMv7 Processor rev 0 (v7l)
BogoMIPS : 6.00
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32
...