Brand new rebuild, oil leak

So I’ve just purchased a truck, 2007 W900, from a dealer in Dallas who stated that the truck had just received a fresh rebuild on the C15. I have paperwork with the serial number showing $17,000 of work done. I called the shop that did the work and they told me that they used OEM parts. I planned to dyno the truck before I bought it and had it scheduled but wasn’t told that where it was scheduled was actually a Cummins factory shop. They didn’t know that it was a Cat motor and kind of laughed when I showed up. They could have told me HP numbers but nothing else. I was pretty pissed because the dealer had not told me any of this before I drove the 10 hours to see the truck. Maybe I should have just driven home but I talked with some guys who have been driving longer than I've been alive and was advised that with the paperwork and no obvious blowby through the vent or dipstick tube that I was probably good to go.

So I went ahead and purchased the truck. I drove it home and it did fine, no issues at all. The next day I popped the hood and noticed oil in several spots, including what looks like the head gasket as well as the compressor. I need to get some pictures for others to verify. So I guess my question is, do I have any recourse here? Is there a possiblity of any warranty if it was in fact OEM parts used? I'm kind of freaking out because I paid top dollar for the truck, it would be a very bad thing if it required serious work before it even hauls a load. I plan to contact the dealer as well as the shop tomorrow but I'd imagine I'll be blown off. Any advise is appreciated.

 

Didn’t end up doing the dyno. The Cummins shop didn’t know much about the older Cat motor and would have only been able to tell me HP numbers. I drove the truck probably over 100 miles just doing test drives, most of that pulling a trailer. I had the hood open multiple times before actually buying the truck and nothing was showing. It was only after the 700 mile drive home that I noticed anything.