LC will eventually catalog this, but it could take years.
IJS is very limited in staff. I don't know when they'd get around to organizing it. On the plus side, they would probably let a serious researcher look at the material even before it is cataloged. LC will not let anyone touch it until it is 'processed'.
I wonder if there is some sort of lead sheet for 'Solar' in this collection, since allegedly he is the real composer.
Bertrand.