Solid wide oak floor that we refinished & all the built-in natural wood cabinetry had leaded glass doors as were the windows. 

Account Closed starting on the exterior / rebranding first is a good approach, as you want to give he apartment a newer, more upscale image.You should naturally weed out the less-than-desirables as you implement your rental increase, this is also where you'll have vacancy opportunities to renovate units. 

Humans have a non trusting and skeptical nature.

I am not accusing you, but it's happened in the past multiple times here on Bigger Pockets in posts like these.Could you explain further about the many hidden problems of the house and the nature in which you addressed all the issues?

Hopefully it will come natural to me after I start getting some experience and knowledge.

You sometimes have to remove the pad, as well.If the urine soaks into the subfloor, you may have to paint the subfloor with an oil-based Kilz or other primer that can seal in the odor.

The dilemma I have with selling is that it’s an area with high oil and gas work.

Single familyPros - available at every price point - easy to understand - comps are relatively easy to determine - numerous exit strategies available - less complex to rehab- less complex to BRRRR- better likelihood of natural appreciation - Less turnover - Fewer tenant headaches- Tenants pick up most/all of property expenses (also, no common areas)- Tenant more involved in upkeep- More financing optionsCons - a lot of competition (regular buyers, other investors)- inherently slower to scale than multi familyMulti familyPros- scale up is built in - more cash flow vs amount invested?

If there is a well house, tenants are tempted to store chemicals and oil near the well head.  

They take pride in the community and if you care for them properly you will find them naturally policing the park like an owner.