I obviously have not considered your specific fact pattern so I won't comment upon it, but care is generally warranted with these types of fabricated transactional vehicles.

I heard about pre made fabricated storage, How that works?

Also, how can you say with such certainty that the OP & his sister have totally fabricated this story? 

Just like back on the ranch as a kid, our pig Scarlet was fun to raise, but she was also delicous to eat.

If a PM fabricates, adjusts or fakes a vendors receipt to show that work was completed when it was not, or changes the price, what legal ramifications could they be facing?

Whether the story is true or fabricated is irrelevant.

Has been in the property for 10 years and is a good tenant otherwise If someone has finances so delicate that he cannot pay $200/month based on section 8 affordability guidelines, then he is a no-pay crisis waiting to happen.  

He fabricated a new pan and replaced a shot king valve on the AC for a total of $1K.

Call around your local fabricators.

They include: the sale of finished products, materials, or merchandise that are not fabricated into and do not become a part of a structure under the common law of fixtures; an owner who contracts with a registered contractor, but not if the owner performs the activities of a contractor for the purpose of leasing or selling improved property owned for less than 12 months; any person working on his or her own property or residence, but not if the person performs the activities of a contractor for the purpose of selling, demolishing, or leasing the property; and an owner who performs maintenance work on his or her own properties, or who uses his or her own employees to do such work.