After looking for a bit you should be able to get a pretty good feel for what is typical for the area and vintage of property.

Be very specific it is you want (number of units, vintage, rents, etc). 

and oregon is prone to having bad years ( much more weather) So thats why Napa Sonoma cental cal are world class consistent vintages.. some better than others.. 

Maybe you prefer properties that are vintage or historic.

For example, if you are only looking for b/c class properties around 30 units in New York and roughly a similar vintage, then you can get a quote on 2 or 3 of the properties to establish a rough idea what the cost will be on similar properties.  

The home is 1920s vintage and the outside is in terrible shape it will need a ton of work.

This is very similar to the way you would price the sale of a single-family home:  look at the comps.You want to find properties close to the subject, of similar size and vintage and with similar units. 

The main thing is you have modern avionics and a plane with no rivets so they are so much faster than the other vintage aircraft that are still 40s and 50s technology. 

I'd advise you to focus on similar comps, meaning, properties within 1-3 miles radius and of similar vintage (5 years above/below the target property vintage). 

I restored vintage cars and enjoyed every minute of it.