Hello Ricardo,
the top wood is Schedua; I was pretty sure when I saw the picture, so I though it would be easy to tell which serial number is the real one.
When I went to check, however, I found out that 77-857 and 77-858 are built exactly the same, so I don't know which one you have.
At any rate here are the specs:
Schedua top & back
mahogany core
maple/purpleheart neck
ebony fretboard
vermillion peghead veneer
brass hardware
mother or pearl ovals
completed October 1977 (either the 7th or the 20th)
That's it
Valentino