It seems that the City of Portland is not (yet) interested in a museum concept
being promoted by a local shortline. Maybe they will come around.

I have not heard lately if the 4449 is moving to any given site yet...
one location I had heard of, near a science museum, was full of limitations.

http://www.oregonpacificrr.com/OPTM.html

I'd sure like to see them find a place where they could install a turntable and possibly even rebuild a roundhouse. I don't know if either of the proposed locations are suitable for that, and there's probably not a lot of other viable options.