I’m interested in buying a used Blackwood Flute from an Individual in Scotland.
I live in the US
Any Tips regarding who to use as a Carrier, mailing Tips, Customs Etc? 
Do not ship if it contains any ivory.
ParcelForce (UK Royal Mail parcels). You want a carrier that delivers in the U.S. via the USPS, not DHL or FedEx (who tend to collect additional fees). Declare the wood on the Customs form - scientific name “Dalbergia melanoxylon” is best. If it’s used or antique, mention it.
There are also numerous item pickup, pack & ship outfits in the UK that can process (for instance, if you’re picking up from an auction house). I used Jentel Packing. Also available are Pack & Send (co. name) shops.
Kevin Krell