I found this Robert Taylor. I know he's tricky with secretaries and this one looks slowly written, almost drawn to me. But maybe it's just carefully written and authentic.
Well, that was a good tip from you with that pic you posted from that very respectable source. It turned out he had one more Taylor in his portfolio, and both looked very much like the one I posted, in dedication as well as in signature. Size, space between letters and angle seem to fit perfectly to the one I posted.