I believe they stopped using knob and tube wiring sometime in the 40s.Roof - Of course in that amount of years, most likely the roof has been replaced at least a couple times, but this is also a big ticket items to look closely at.Plumbing - I think it was sometime in the 80s when PVC pipes were starting to be widely used.  

Transfer on death deeds are not widely used, and in fact, the last that I had heard, were only recently extended in terms of availability in California. 

In the short term rental business there seems to be a wide range of different types of rentals that are apples to oranges, especially from a financial perspective.

Wheat Ridge is a wide, flat city that butts butts up against the city of Denver on Denver's west side.

@Ray Loveless You can't look at this as a state-wide issue...sure there is revised code...and yes, comparatively the ORC is pretty landlord friendly.

The 50% rule states that approximately 50% of EGI will typically be consumed by operating expenses.While the 50% rule provides a quick estimate, actual expenses can vary widely depending on the property type, location, age, condition, tenant mix, and market conditions.Here's an example: if a property generates $200,000 in EGI per year, the 50% rule suggests $100,000 would go towards operating expenses like taxes, insurance, utilities, and property management.

So, I don't think comparable sales of properties that can be built on would be very useful and non-buildable lots are likely to be all over the map depending on a wide range of factors making each of them unsuitable for building.

All available loopholes, which allowed deregulation of units were, unfortunately, closed by our elected officials, except the substantial rehab strategy, which requires 80% vacancy throughout the building and 75% replacement of all building-wide systems, you are essentially forced to renovate the complete building and still at the mercy of DHCR.. which has the final saying

Most lenders are going to be limited to using the lower of appraiser's opinion of market rent or the actual in place lease (or in some cases 110% of market if lease is greater) so it sounds like you just need to roll the dice on a new appraisal but I'd recommend having some rent comps on hand for the appraiser up front just to avoid the same issue.  75% cash out pending positive DSCR is widely available at most DSCR lenders. 

You essentially have essentially cast a super wide net and are going to get a ton of sales responses, but what I gather from your post that what you really need is a mentor/like minded investor to help hone in on recognizing good deals, narrowing your focus and absolutely protecting your capital.