John, another alternative is just getting one of the alloy bases that have been around since the PT's first came out, they still have the single handle bolt but I have not seen any problem with those in that area and I have had a number of those here. If it bothered you, you could weld a bracket to the side of the handle and bolt it to the chassis, never be a problem ever again
Those came out in 1992 to replace the thumb latch design. Powertorques were introduced 8 years prior.
The single bolt top mounted handles don't seem to prove a problem on the alloy copy of the steel base, as they don't flex.