Fairlight-CMI

I was thinking about refinishing the MDF case on the music keyboard and 
had a couple of questions:

1) Is it a good idea at all, or is it better, from a 
value/collectibility standpoint, to leave the original finish, 
blemishes and all?

2) Does anyone know the type of paint used originally?  I'd like to get 
as close as possible to the original finish.  

3)  What primer would be appropriate?

Cheers.