@MJ154 , section 1015 of the Internal Revenue Code clearly declares the basis of a property acquired by gift is the same as the basis of the donor at the time of transfer. US tax code generally is the same whether a n asset ( specifically immovable ) is located in the US or elsewhere. Thus the rules on the basis ,and adjustments thereof, operate just as if the asset and taxpayer are domestic.
The situation not clarified is what to do when the asset and the owner did not exist ( for US tax purposes) prior to a date certain --- when the tax payer becomes a US person. This becomes even more complicated when the taxpayer ( and before becoming a US person ) has paid taxes to a foreign govt. to recognize FMV of the asset ( e.g. wealth tax which taxes an asset on the incremental value of the asset i.e. to bring it to FMV for that particular year).
While these musings may not help, the onus is on the taxpayer to justify the basis of the asset ( no matter how acquired) and thereby compute the gain/loss on alienation of the asset ownbership.
Hope this helps. Is there more I can do for you ?
pk
