I've toyed with the idea of a top of line one that even does temp control, but I could never justify the price and I didn't like the looks of them.I talked with an amazing custom furniture builder (modern furniture) that I know.  

Keep it modern-ish, but it's tough to get your money back out.Jump on it and Good luck!

@Ernest GrindleIt likely is a modern-day mini-home / manufactured home / modular home which was delivered on-site in one or two sections and set on its foundation.Around here they no longer call them trailers unless they have an undercarriage/wheels :-)As far as being a rental, your tenants are not apt to go into the crawlspace.

No bank is gonna loan you a penny under those conditions and most hard money lenders would probably take a pass as well.Only a private lender( millionaire) might be willing to help for a huge interest rate that will make you cry.What do you want the cash for exactly,it makes a difference.My advice since you have 5 free and clear properties is too to sell the 3 worse ones for whatever cash you can get and invest it in repairing the best two into modern top of the line properties charging premium rent and maximizing the ARV.

Taking that into account, you can spend just a little bit more in my scenario and you will have a nearly new one owner car with modern safety, gas mileage, entertainment system, etc. 

If they don't partner with anyone or give referrals, then I'd just call around and get estimates from several, Foremost, American Modern, etc.  

Or2) Update the bathroom and make it more modern?

INVESTMENT ASSETS TO GROSS PAY BENCHMARKS TO ACHIEVE RETIREMENT GOAL Benchmark for Investment Assets as a Ratio of Gross Pay by Age Age From to 25 to 29 0 0.2 30 to 34 0.6 0.8 35 to 44 1.6 1.8 45 to 54 3 4 55 to 64 8 10 65 to 16 20 So, if you are 45-45, your investment accounts should be 1.6 to 1.8 times your annual salary.

Without the time savings, the monetary return would never hit its benchmark.  

A Modular home if modern will appraise the same as a stick built all else being equal (style, size, fit & finish, location, etc), in fact there is no difference in the appraisal forms.