Arfa Daily wrote:

snip

Tried a very small amount of lead free solder, didn't like how it
behaved and then set it aside to keep using leaded solder until I
can't get it anymore. The antique stuff I work on has leaded solder so
it seems proper to repair it with the same type solder

Indeed, some experts recommend this, saying that mixing leaded and lead-free
in the same joint, reduces the potential integrity of that joint

Absolutely. When repairing old kit use leaded solder.

Graham