Kinda late to this party but, if the OP already has Nikon lenses then for a lighter body why not a FE? They seem fairly plentiful and not too expensive. Don’t know about reliability but I’m sure Nikon users could fill in that detail.
FE is a good camera indeed. Tactile joy, might I add. I am yet to see a camera with better feel to film advance than FE. The only drawback of I can point out is: it is very tricky to use AE lock in portrait orientation. Feels like I am twisting my fingers. It has a metal shutter, better flash sync and is as light as any single digit OM body, although bulkier. Same goes for the lenses. A true advantage of OM system lays in its lenses and their compact size.
As for reliability, you can break walnuts with FE and still keep photographing after. Of course they break too, just like any other camera, but their faults are mainly electrical and we can't avoid such things in cameras older than 30 years, can we?