From what I now understand, if the 3 letters are separated, it's an SSD logo so, like you just mention, this one is a Spector logo. Thanks! @j.kernodle
I did some reading about the "non-compete clause" and the "Kramer era" but the whole thing is still a bit sketchy so I'm still learning. Thanks for the precision about when he got back his original logo.
Last question, what would be a fair price for this model in great condition (minimal wear by playing only), no case or extras?
-Quilted maple body
-Pau Ferro slab with dot marker
-34" scale/ 24 frets
-9v Aguilar OBP-1 circuit
And oh yes, is it me or you don't see them too often on the used market (or common, very common,...)?