In our project actuals there was  ~8K in costs that would not have occurred if we did not have to clean-up after the pets.

In my opinion, there's not substitute for hiring a contractor who specializes in stucco and pay them to access the project on-site and quote the job.  

Based on my projections, I would be able to purchase the 2nd rental after 3 years.I would then continue to use this plan (saving all rental income towards down payments) to purchase additional single family rentals around a similar price point of $150k.  

Real estate investing 101.Hard money lenders usually lend 65-75% of the project cost, charge 12-14% and 2 points for origination. 12% fees is a huge red flag, the only you'll get from "Midwest Corporate Credit" is an ulcer from the stress of losing $7,200.Raising $60,000 isn't too difficult, if you talk with friends and family and maybe a real estate attorney or two you should be able to raise it.

Been thinking about possibly making this home our first fix/flip project.

If you aren't concerned about equity, couldn't you just buy another 4 unit that is move in ready and not have to deal with the massive headache of a 50k rehab?

Achieving economies of scale may best be attained through volume, but learning how to do it on a small scale will pay generous dividends later; pitching the concept to investors will be much easier when you can show concrete results, and extrapolate from those results instead of being forced to rely solely on projections from a concept.

I have been having trouble locating favorable refinance rates on my projects.

You may want to find out if this is DIY projects (and how much experience they have) or professionally done.  

I are on our 50th project.