Retractable seat belts in '72 vert

My '72 convertible has "plain-jane" lap belts in the front seats. Judging from the assembly manual, it appears to have come from the factory this way.

It's not unusual for one of the kids to jump out of the car, slam the door, and when I get home I discover that the passenger belt was flapping all the way. Frequently when I get out on the driver's side I have to make a conscious effort not to close the door on the belt.

To avoid these problems, I would really like to install retractable belts in the front. The back isn't any big deal, but retractables back there would be nice too.

I've been trying without success to figure out from looking at pictures and diagrams if the retractors from a coup or fastback will bolt into my convertible. I searched this forum, but didn't find any discussion about this. I also bought some "aftermarket" retracting belts, but they won't "bolt-in" and I'm not ready to resort to drilling, cutting, or welding.

Has someone else done this? Do you know which retractors are a "bolt-in?"

Thanks.

Wayne.

** bump **

Nobody has any ideas?

Thanks for responding.

I see the sets on eBay periodically. My real question is: will a set from a coupe or fastback work in my convertible?

Well, on the outside chance that somebody else was wondering, I'll try to answer my own question.

The retractors from a coupe or fastback do not work in my '72 convertible. Bummer.

Apparently they slightly modified the floorboards sometime during the '72 production run. If I understand correctly, my car is an early '72, with floorboards like a '71 model.

Can anyone else shed some light on this?