There are plenty of “reliable and quiet” options without getting much more modern than that. However, this site is primarily about keeping things period appropriate. Sorry to hear about the shift problem on the lark though the early selectric systems where known for it. Finding similar motors to that in a mechanical shift is relatively easy. The mechanical shift engines also had low failure rates comparatively.
I think if you are planning to re-power with anything 90s or newer this site isn’t going to provide you as much help as a local marina would that is after your hull is repaired.
If you have a horsepower rating for the hull that would help us to give you what options would be suitable whilst keeping your boat period correct. In my opinion the older hulls look so much better with the right style cowl pushing them.
