One option is to fix it up & then borrow on the equity sort of BRRR style.

In regards to skip tracing, find and use a company that has flexible pricing options, volume discounts or discount memberships; this will keep your cost of skip tracing down.

One final source I will give you is signs.

I will have a property or 3 that I've located,  found owner negotiating seller terms,   knowing I don't have the credit or capital or network for sourcing either,   I'd go to sites or platforms that want partners for 50 50 deals..   

Understand different options we have in RE market 2. 

As an overseas investor, I've been carefully evaluating different options and have narrowed down to a particular buy box that I'd like to share with you all for your insights and opinions.

BP is another of those sources as you can look at reviews on the profile page and actually talk to people here on BP who have used a QI. 

There are a lot of investor interest that does not come from BP so I think your sample size is just pooling from one source

Can I use Solo 401(k) as source of funds to pay 25% down and leverage debt for remaining principal amount to purchase a duplex that I will owner occupy and rent the other unit?  

Was this not an option for your contractor?