My husband did occasional work on Henry’s Ranch, Henry promised him two Cattle feeders in exchange for Labor. The cattle feeders were built by Henry

The way your question reads, I don't know whether "the ranch" is a separate entity (e.g. a corporation, llc, etc.) or not.  In other words, I don't know whether your husband's contract was with the ranch, or with Henry personally, but either way you should (barring other facts not mentioned in your question) be ok.  If your husband contracted with Henry, and you are saying that the daughter is now a conservator or guardian for Henry, the contract is still valid assuming that Henry had the mental capacity and right to contract at the time he reached the agreement with your husband.  If the contract was with the ranch, and assuming that Henry had the authority to enter into contracts for the ranch at the time he contracted with your husband, that contract is binding on the ranch regardless of who is now running it.  Even if the contract was unenforceable for some reason, such as that Henry was not competent at the time of the contract, or lacked authority, your husband would still be entitled to what is known as "quantum meruit", the fair market value of the labor he performed - he might not have the right to get the equipment, but he should be able to collect the fair value of his labor in monay.