Good luck - that's going to need a lot of work. Comparing it to pictures of Hines Mikados, it might use some Hines parts, but a lot of it looks scratchbuilt. Looking carefully at the photos on eBay, it looks like it might have properly equalized drivers - if it does, that's really neat.
Try looking for an All-Nation Medium tender, I believe they use the same exact castings as the Hines tenders did. They're pretty accurate models of USRA 10,000 gallon tenders.