So....my wife and I drive about an hour to go pick up this used Model D for $600. Pull up to the house, she opens the garage door, and I see it.....the wooden handle

So I know immediately it's the Model C. Now, $600 is a decent price for a used Model C here in Texas, I'm finding out, but I could have driven 15 miles and picked one up in Austin that I had already seen. The chain was visibly rusty, but while I was there I looked it up and saw how cheap they are ($18), so I figured it wasn't a deal breaker. Felt smooth when I tried it out, but I had to let her know it was a Model C, not the Model D she thought it was. She asked what the difference was, and I explaned Cs were made between '93-'03 and that Ds are the current models made from '03-present.
She apologized that she was mistaken (I couldn't see anywhere on the rower what model it was) and offered to knock off $200. I already had my heart set on a Model D, but I figured for $400, it was well worth the trip. Think I'm probably going to get a new chain, even though this one seems to be working fine, and the ergonomic handle (think the chain comes with chain oil?).
Would this be a good resource to figure out what else I should look for before I order just in case there's other stuff that I should get?....or should I just call Concept2 and talk to them?
I did have to at least check it out when I got home, and I have to say that rowing is EXHAUSTING! I've only rowed about 750m prior to this (250 when they showed us at CrossFit how to do it and another 500 as part of the workout of the day), and I decided I'd start off by getting my 2000m time....yeah, easier said than done. Took me 12:15, and my right arm felt like it might fall off about 1000m in
Whole family got home and tried it out (kids have already rowed a 500m and 1000m - they're 7 and 10. Too young?) and we had a 500m contest. About halfway through I thought I might break 2:00, but about 7/16 of the way through I quickly realized I was about out of gas. Coasted in with a 2:12 500m.
You can probably tell from my rambling I'm pretty jazzed about the whole rowing thing. Heck, got our butts kicked at CrossFit this morning and I didn't think I'd be checking out the rower until tomorrow, but I just couldn't wait.
Thanks in advance for all the knowledge and advice I'm sure the get from this great forum (and if I'm wondering where to gamble for free on the internet, some dude posted about 20 times to help me out).
Peace!