I went to the junkyard today and got a female seatbelt out of an 80'* S10. I left the stock seatbelt in place, just removing the bolt from the floor. I bolted the S10 seatbelt into place...voila...It works!. The S10 belt is about an inch higher than the Bonne belt, so there shouldn't be any geometry issues.
I just did not feel like taking a junkyard Bonneville seat apart to get the seatbelt off, let alone my seat.. (The belts I had disappeared in my move)
Grand total $5.
And I have a seatbelt again!!!
On a side note, I latched the driver'* side belt into the passenger'* side female end. None of my passenger'* used a belt, so it was a good temporary move for me...