If sending directly from a PCB shop, and the value is less than the import threshold, then there's no problem.
Simply tell the PCB shop to put the statement in an envelope and stick the envelope to the outside of the box, and
all will be well.
If the value is more than the import threshold, then ask the PCB shop to lower the value on the statement to
an amount within the import threshold.
If they won't do that, in this case, you need to take delivery of the item, and then send it to me as a personal gift.
In any case, I request that you print out the customs declaration form that I've written up
will pacify customs and allow the goods onwards. Fill this out and put it in
an envelope and put the envelope inside the package. Write on the
envelope 'Customs Declaration Enclosed'.
After you wrap up the package, on the customs/export label declare it as...
"used arcade game"
and value it at somewhere from US$20 to US$100 (if it's just 1 PCB in the box)
If there's a lot of PCB's and the box is large, you'll have to split up the package and send them separately.