Nice looking bike and the cut outs are mad, particularly those pedals
However to my eyes , for a weight weenie build, the bulky, heavy looking saddle really jars and, even though you mention the indentations, it does look as if it's nose down which spoils the overall look. Also the cage, which may be period correct, doesn't match the overall aesthetic of the bike. Add to that the colour clash between the stem and post and it's almost there but not quite. Nice photos though.
First of all the bike was not initially meant to be a weight weenie bike. The frame is simply to heavy for that. By simply exchanging the fork out with one made with "road" blades (instead of the round extra beefy track ones), you would be able to drop perhaps 100 grams. The Selle Royal Contour Superleggera saddle was in fact one of the first "lightweight" saddles having an alloy undercarriage (without speaking of the Idéale saddles with alloy undercarriage that nonetheless remain very heavy.) It is considerably lighter than such saddles as Unicanitor, Concor (even the superleggera model), Turbo... As regards the stem and seatpin being different colours, this speaks of the mid-80's. As regards the bottle cage, we will need to disagree as I find it to be very elegant and among the lightest of its time.
PS: as already mentioned, as the bike now stands, the bars and stem are now raw metal (no more black stem) and the saddle has been replaced with a Concor superleggera.