The PayPal user agreement disclaims all warranties, either express or implied. The service is offered entirely "as-is." There is no promise that PayPal will maintain account information on your behalf. Consequently, if PayPal doesn't produce it to you, then it's not liable, because it never promised to save it for you in the first place.
Also, the user agreement requires arbitration for all disputes with PayPal. So, even if you could bring a claim against them for not producing the account history, you would be unable to use small claims court. This is actually a good thing, because you would probably never be able to sue PayPal in Vermont small claims. You would have to sue them in California.
PayPal is not a bank, and it is not subject to most ordinary federal or state regulation, except for flatly fraudulent or criminal activity. However, PayPal is what is known as a "third party payment processor," and, under IRS regulations it must maintain the monetary record of each transaction for six years, though the detail is the amount, date and time of payment and transaction payor and payee.
So, if you were to sue the vendor for breach of warranty, you could subpoena the third party payment processing info from PayPal, and it would have to produce at least that much info (because it must have the information).
I don't know if that would be sufficient to get you what you need to solve your warranty issue -- but that would be the limits of what you could obtain under the circumstances.
Please let me know if I can be of further assistance.
Hope this helps.