Did you do a bearing repack and check the brakes when you got the tires? Ready to roll is good but stopping is important too. Very nice of mom and dad to give you their trailer. Looks good too and like others have said..... if they want you to prove your 10 yr old unit isn't dilapidated then find another CG. You do need to find the pin weight and then after you get loaded up for a trip you need to visit the scales to know exactly you weight numbers. Payload and rear axle weight rating are your important numbers. Now go have fun.