First of all, after your husband's ex-wife died, the property should be divided. Give the husband 1/2 of the property first, because it is his own part. The remaining 1/2, as the legacy of the ex-wife, is * * * by your husband and their three sons, which should be 1/4. In other words, at present, your husband owns 5/8 of the property rights of this house. And it's his personal property before marriage, not your husband and wife now.
Now you want to share the property, which means you want to change your name. You should compensate the other three sons for their property rights in cash or other ways, and then they will make a declaration of abandonment. At this point, your husband took his ex-wife's death certificate and his third son's declaration of abandonment of inheritance and went to the real estate transfer hall to change his name. At present, inheritance and renaming do not charge taxes and fees, only the cost of work.
Your husband is free to dispose of the property after obtaining all the property rights of the property and changing its name.
Now you want to use your husband's personal property before marriage to borrow money to buy a house. First, you have no right to dispose of it, and your husband can only mortgage the loan. Second, your husband, as a property owner, can use this house as a guarantee to lend you some money. This is the so-called mortgage consumer loan. However, the current mortgage consumption loan policy is tight, and there are specific provisions on the age of the house and the loan ratio. Specific policies can be consulted with local banks.