Any cautions on buying an RV with a lien on it, please ?

I literally just finished this process 2 weeks ago. Pay off the lien only as a good faith down payment to the bank, then pay the balance on delivery with title.

Banks don't store titles any more, especially big banks. They pay a holding company for file services. It could take a while to get the title in hand. Also, get the complete bank name, routing number, and account number so you pay them directly.