1970 Paco Gorospe Abstract Oil Painting

Paco Gorospe was called the "Picasso of the Philippines"and I was told his abstracts,especially his earlier ones, are very sought after. I saw one of his abstracts from the 1980's listed at a Gallery online in 2001, before he died, and it listed for 3500.00 and was about half the size of the one I have.
This abstract is really nice and quite large and it's one of his early pieces dated 1970 and still has his original paper studio tag and information from his Philippines studio on the back. I think the painting is in excellent condition, but I listed it as good because it might need a cleaning and I am far from an art expert.
I am debating on whether to sell this painting, but I have no idea of where would be the best place for something like this and I really need to find out a value for this size abstract, as I have only seen a couple of his abstracts and none where this large.
It is also the original framing done by Paco Gorospe.
I would greatly appreicate and info or opinions....thank you!!