[geoff]

I hate lead-free solder and all the stress to components, tools, and PCB
that rework entails when repairing gear.

Ideally I clean off the crappy stuff as best possible, and re-solder
with regular 60/40.

But what if I didn't clean off the lead-free ? What are the implications
of a blend of lead-free and leaded solder, electrically, physically, and
chemically ?

geoff