Ya those axle nuts r heavy.
Front Road wheel/hub with titanium skewer!

Or if you wanna keep things track and Italian,
a MICHE Pistard wheelset can be had for $270. Weight is 2060 tho.

Tubes n tires can be heavy too especially tires that have very good puncture protection so
So getting super light tires might not be good for rear if you skid stop alot.

Cut down carbon seatpost to shortest but safe length.
Try narrow alloy flat or riser bars instead of dropbars.
And how bout a carbon fork?

Might be able to save weight in the pedals too, dunno if nylon toeclips will be lighter than steel,
Or if practical for the type of riding you do, going clipless?

External bb cranks and external bb might be lighter than yur current setup.

1/8 chains can be really heavy, you can save weight here too.