Short answer. Yes. Article 1991 of the Civil Code provides that a depositor's heir who, in good faith, sold property they did not know was deposited is bound either to return the price already received or, if the buyer has not yet paid, to assign to you his right of action against that buyer.
What the law says
The depositor's heir who in good faith may have sold the thing which he did not know was deposited, shall only be bound to return the price he may have received or to assign his right of action against the buyer in case the price has not been paid him.
Civil Code, Article 1991 — Heir Who Sold the Deposited Thing. Read the full provision →
The heir's obligation is limited to price received or assignment
Article 1991 provides that a depositor's heir who, in good faith, sold a thing they did not know was deposited shall only be bound to return the price he may have received or to assign his right of action against the buyer in case the price has not been paid him. Since the buyer has not yet paid, the heir's obligation under this article is to assign that right of action to you rather than to hand over money he does not actually have.
Why good faith changes the remedy
The article's protection turns on the heir having sold the item in good faith, without knowing it was deposited property. Because of that good faith, the heir is not treated the same as someone who knowingly sold property that was not theirs to sell — the law limits what can be demanded from them to what they actually received or stand to receive, rather than exposing them to a broader claim for the value of the thing itself.
What assigning the right of action means in practice
Assignment of the right of action transfers to you the heir's own claim against the buyer for the unpaid price — putting you, in effect, in the heir's shoes as against that buyer for purposes of collecting what is owed. This is why the remedy is framed as an alternative to returning the price: the heir cannot return money that has not yet been paid to him, so the law substitutes the right to go after the buyer directly in its place.
What the article does not address
Article 1991 fixes what the heir owes you — the price received, or the assignment of the claim against the buyer — but it does not itself spell out the mechanics of how that assignment is carried out, or what happens if the heir refuses to cooperate with executing it. Those questions depend on the general rules governing assignment of rights and on the specific facts of the sale and the buyer's obligation to pay.