The real estate melt-down in 2008-2009 necessitated my unretirement...After looking for some other way to rebuild my retirement portfolio I have circled back to real estate as my vehicle of choice.

You are going to pay an extra 3.9% on investments outside of tax-sheltered vehicles (since Obama now considers you rich).Unfortunately, there's no way for real estate to lower your taxes.  

Personal loan against vehicle or other asset 

If you meant more like what vehicle, I'm going to focus first on low end fix and flips and maybe do a house hack too.

The Reit or whatever investment vehicle that part does not matter as the principle is the same regardless.

Rent out your current house and invest that money by paying down the mortgage of the rental house or finding a new investment vehicle for your future.  

@Jeff Thompsonwhen you sell investment owned by the IRA - the gains are sheltered from taxes (because IRA is tax-deferred vehicle) and when IRA-owned investment produce income or cash-flow - it must flow into the IRA and also will be sheltered from taxes (unless the income is unrelated business taxable income). 

A 401(k) is generally the better vehicle, provided one qualifies for it.A strategy that could be used is the use of a 401k loan - i.e., a loan from the 401k - which can be used for any purpose.

I don't look at mutual funds as a vehicle to create wealth, but more of a place to KEEP existing wealth where you can get a modest return so your wealth doesn't get eroded by inflation over time.3.

Chris Mason  manufactures of Of these units by ALL means made multi family duplex units I have bought and installed many .. in Oakland no less.as long as they are affixed to a Permanent   foundation and removed from the motor vehicle registration they are considered stick built homes..