This is going to be difficult I would guess. I'm not sure if a private attorney would handle this on a pure contingency because it may not economically be worthwhile. At the same time, a pure hourly rate would would be uneconomical for you.
I think your best two options would be to either (1) find an attorney who would accept a small flat fee and a contingency, or a (2) pro bono attorney.
Best of luck to you.
I am not your attorney. I do not represent you. This response is submitted for informational purposes only. This is not legal advice, nor is it intended to be taken as such. Anyone considering the above referenced situation should always consult an attorney within the jurisdiction before taking any action based on this, or any other information
Elster is rightly skeptical. An unsigned will is probably no help. And who knows how many other people the deceased promised things? So you may end up disputing the gift of the truck. If it is not worth much, you may need to represent your self in a lower court. If it is worth a lot, a lawyer might take the case. You could afford a consultation. Put together all the documents and names of witnesses and what they would say. Then go see a lawyer about it. Act quickly before the state is distributed.
DISCLAIMER: The forgoing comment is for general educational purposes only, and is not legal advice upon which the reader may rely as the commenter has no actual knowledge of the facts of the case, has not interviewed persons or examined evidence, and has not researched the applicable law. The comment is based only on the facts provided, which are extremely limited, and may or may not be true. Complete defenses may prevent the success of any claim. Competent legal advice should always be obtained before taking any legal action or filing suit. Readers employ any information provided herein at their own risk.