Earlier someone said they might be traveling to Costa Rica. Perhaps they would be willing to come to you and pick up the boxes?
Sure! I would need some advance notice because there are no boxes yet. The boards are all in small plastic storage boxes (aka, Tupperware) and I need to bag, label, and box them up. I will contribute the cost of the boxes and packing materials. The will need invoices for each box as well.
Perhaps the volume of stuff will not be so bad when they are removed from the plastic boxes and bagged. I still think it is around 5-6 freight boxes -- not something that can be hand carried. Shipping to Brazil would still have to be arranged. Costa Rican snail mail is not too expensive. Most Latin American countries will require and invoice with a value associated with each item. The customs fees/taxes will probably be very high. A wild guess would be a couple of hundred dollars per box????
Shipping to the US is far easier. I work with a private shipping company that shuttles things by sea or air between Miami and Costa Rica and the US will not charge any customs fees or taxes on receipt.