A White Bros ti bb is 162 g, a Campagnolo Super Record ti bb is 204 g. I'm guessing those would take 130-170 g off the PSV, or 4-6 oz. Maybe all you need?
Problem is, I've never encountered a TI BB I can afford or use.......yet....
Same with Al FW's...... Maybe I'll just "steal" the Regina Ameica Superleggera FW I have on my project Medici for now? It's not 100% Al, but it might get me real close to 19.0 pounds!....But dang!, it ain't French!