This was a traditional home purchase with conventional financing.

conventional financing with 5% down.

. - offer a short-term strategy for them to fund your long-term hold.You can offer 8-11% on their money for a medium term loan (maybe 12-36 months) so you can perform a cash-out refinance through conventional or commercial means after the property has been renovated.

I used a conventional loan from a local credit union, Michigan State Federal Credit Union. 20% down. 

Just how market is for this type of lending if you looking at conventional 30 year fixed.  

Some private money had programs for purchase price plus repairs after a cash purchase but I am outside of required timeline.Can complete out of pocket and refi when seasoning hits a year in July.Commercial lender doesn’t want to do while down to studs, neither does conventional obviously.Read articles about velocity of money a few months too late.Not asking for lender referral rather if there is a type of lender out there that handles such a situation?

Would it be possible to do a mix of a conventional mortgage and then some seller financing? 

If they weren't prohibiting conventional loans they may be trying to steer a purchase to a homeowner especially if they have a stated period where only loans from homeowners will be accepted.

HML to start and will finance out with conventional 4% rate How did you add value to the deal?

There's tons of people on conventional loans that airbnb their houses when they go on vacation or just aren't in town.