Buying with both 1031 and mortgage - title and spouse questions

[Callie Edward Muckelroy]

Good morning. I am trying to work out how a 1031 exchange would work when things are in different spouses' names. My wife and I have a CPA and 1031 Intermediary involved here, but they are both on vacation for the next few days. In the mean time, I have done some research, and also thought I would post here for advice.

I'll frame my question as a hypothetical, since I'd rather not openly share every aspect of the transaction we are about to undertake. I also hope the answers given can help others.

Let's say I own a property under my name alone, and I want to sell it via a 1031 exchange. The earnings from the relinquished property will be $500k. Let's say that I use the funds to buy two properties:

1 $300k property bought in full with $300k cash from 1031 exchange

1 $300k property for $200k cash from 1031 exchange, and $100k from a mortgage.

Due to various problems, let's say I am unable to get a $100k mortgage for the second property, but instead, my wife takes out that mortgage. I've done a lot of reading on this problem, and it sounds like it is possible for me to own 2/3 of the property, and my wife own 1/3 of the property. (Correct me if that is a wrong assumption.) 

Now, let's assume that after 5 years, we have paid down half of the principal of the mortgage, so only $50k is still owed. We decide to sell the second property, and it sells for $400,000. How can we do this via another 1031 Exchange? Would it need to be done to where only 2/3 of the sale of the second property's earnings is "shielded" from capital gains? Or, is it possible to put both of our names jointly on the entire property before the sale? I would like to do this in a way that as much as possible of the gains from these sales is protected from capital gains taxes, so if anyone has advice on how to do that, it would be appreciated. 

I understand that the "best" solution to this problem might be to get the original property in both of our names from the start. However, that is time prohibitive, since the property is about to hit the market soon, so we must deal with working this out with the resulting purchased properties. If anyone needs to know, we are located in Texas.

Thank you very much!