Welcome to the club... you will get a lot of enjoyment being a part of this group!
Looks like you have a nice D6. The U series D6s are, in my opinion, the best tractor that Cat ever built and I've had most of them D2s, D4s, and D7s. I've had several 9Us and they were my main land preparation tractor for a long time a long time ago. My remaining 9U was made in 1959 and its been in my family since it was new and it still performs like new. If you take care of that tractor... it will take care of you!