Thanks for the lead on TriStarr; Bob's Speedometer was another option I was considering as well.
When I looked a couple years ago there was nothing available as far as a new replacement sender for '68 Bonnie. However, I just found this link on ebay:
67-68 Pontiac NEW Replacement Dual-Line Fuel Sending Unit Catalina Bonneville
https://ebay.us/8AgpVc
Its under $100 shipped. Anyone here have recommendations for or against this?