2oTH Anniversary '81?

OK, so I bought this '81 back in November. 1425 hours. I've rebuilt motor, turning attention to hull/interior. Couple questions:

1): There are 3 stickers with Slalom time/speeds around the interior with a 415 area code phone number along with Berkeley Water Ski Club (Berkeley, Ca) stickers on each side window, so I believe it's seen course duty.. BWSC is 40 minutes away, so I believe the boat is local to me. The seller (owner for 3 years) claimed to have bought it from the original purchaser, but had lost records.
(I'd like to know how to trace boat's origins.)

2): Today, as I was removing things for color sand & buff, I noticed "20TH ANNIVERSARY LTD MODEL" cast into the hull on transom upper left. I've read about the 20A 81's and their unique features (of which mine has none). The boat is still very original, down to the carpet and most of the upholstery.

Now I realize this is not a vintage Ferrari, but is thing any more valuable?
Before I begin my planned modifications which were to include (gasp, clutch chest..) storage/drink holders/stereo, etc. (some of which require a saw or drill.) I thought I'd investigate the 20th A deal.

(do pictures still require web-hosting)

Thanks for any insight

Id love to see some pics. I love the late 70s-thru the early 80s.

I believe the actual 81 anniversary boats had a deluxe interior. The drivers seat was taller
than standard, and had a special windshield - perhaps polished metal instead of paint? Not sure. Alan's former 81 was a true anniversary edition. There are lots of picture of that boat around the site.

BKH

They were all stamped anniv but the deluxe model was different than a standard. As Brian states, seat backs were taller and had full wooden bases, ski lockers on both sides, some had doors covering the lockers, stainless rubrail instead of the rope, silver windshield instead of black, the dash was deck color gel not the black., wood grain dashboard, stainless steel grabs rails . might be a few other things but thats what I remember stood out

Thanks to the many replies.
So, lacking any of the special "Deluxe" features, I have an ordinary, run-of-the-mill '81.
As for my plans for it, that's a good thing.
Again, thanks for the intel.