I'm no wood expert but here's what the USDA had tosay about it: http://plants.usda.gov/plantguide/doc/pg_acsa2.doc
(attached). They describe it as:
"fairly hard, even textured, rather brittle, easily worked and is used for furniture, cabinetry, paneling, flooring, woodturning,
veneer, musical instruments, boxes and crates, tool
handles, wagons, carts, and rails. Old heartwood
develops a swirled pattern that is sold as “bird’s eye
maple.” Silver maple on good sites can be managed
for timber – it is often cut and sold with red maple as
“soft maple” lumber."
Based upon that, it sounds like you scored. Bird's eye maple is very expensive and with "mature trees" at 80-110ft tall, it sounds like you got one.
Here in Alaska, 4/4 soft maple (clear, kiln dried) starts at $3.62/bf (6"-8" wide x 14' long, S2S). Bird's eye" starts well into the 'teens. It sounds like you've got a great long-term supply of wood!