A bank may not be hugely interested in lending on them because of their condition, but you should see what they can offer. You can definitely try to find someone to offer a private loan. You could also sell one and use the proceeds for the other rehab. Or you partner with someone, but I would probably try to avoid that.
If your father will wait at least 3 months from the day he took title, he may be able to get a rehab loan, as the HML may lend up to 90% of the as is value of the property as cash back at closing. In addition set up a rehab escrow to fund the project. He may be able to accomplish with no money out of pocket with the exception of appraisal. This is my advice. There are several HMLs to choose from on the site. Good luck!
Depending on the value you can get a short term loan at around 8.5% interest only on a cash out refi
No seasoning needed
Has he thought about maybe selling one to fund the other rehabs?