IMO the weight savings will be negligible with the Kluson tailpiece - should add a nice vintage vibe though, and a set of these not only completes the package but
will save you some weight at the headstock:
http://www.stewmac.com/Hardware_and_..._Bushings.html
You might also try a laminated-plastic (postwar L-7 style) or single-layer tortoiseshell-type (prewar Epiphone Zenith/Blackstone) pickguard, although I think the weight savings will also be minimal...
As far as the bone-saddle bridge is concerned I personally wouldn't use it on a 16" guitar, which generally has no problem with treble response; IME these are intended to brighten up a muddy-sounding 17"/18" comp box (Gibson L-7/L-5/Super 300/Super 400, Epiphone Triumph/Broadway/DeLuxe/Emperor) or add a little "bite" to a "thud-&-mud" electric jazzbox with built-in pickups - bear in mind that an archtop is very much
sui generis, and you'll never really turn it into something it's not. I'd focus on experimenting with string brands/types/gauges to achieve a more subtle and complex coloration; you don't say what you're using right now, but if you're going straight acoustic I'd start with a set of acoustic strings - a little fine-tuning (no pun intended) should get you close to what you're after...