Using ReactiveUI for pass-through values in WPF

Question

I've got a problem that I'm fairly sure ReactiveUI will help with but I can't quite wrap my brain around how to implement it. Basically I have a simple model:

public class Model
{
    public bool IsThingEnabled { get; set; }
    public string MyStringSetting { get; set; }

    public bool IsModified { get; set; }
}

And then I have a ViewModel that can edit this model, or swap out the model for a completely different one.

So it has the IsThingEnabled and MyStringSetting properties but also a Model field/property. Before my approach was to have a property getter and setter pass down to the underlying model, with some extra logic on the setters to update other dependent fields on the Model, set its IsModified to true, raise property changed event(s) and persist the model to disk.

This works pretty well, but the problem is that I have to raise a property changed event on every property when I swap out for a new Model, and it's easy to forget. I was thinking I could use ReactiveUI to streamline this in some manner but so far I haven't come up with anything. I thought about making an Observable and using ObservableAsPropertyHelper but that is apparently geared toward properties with only a getter.

Then I considered using a standard property with a backing store on the VM and a setter with RaiseAndSetIfChanged, but I couldn't figure out quite what Observables or subscriptions to do. I can observe a new Model getting set, but then would still be in the position where I need to distribute property change notifications for everything. And I'd still need to set up subscriptions to pipe each VM property down to the model when it's changed.

Am I missing something about ReactiveUI or should I use a different approach?