Wait for CT249. He bought his back in about 1986 or so. Still has it. Second one in the family. Need lots more info - photos, description.
anyone got any advice on these
I'm totally biased but I think they are a great boat, but with tradeoffs like any boat. What in particular do you want to know and do with it?
As far as performance goes, they have moderately low initial stability due to the narrow stern and round bilges, but stiffen up dramatically once the bulb keel's effect kicks in at higher angles of heel. We tried to do a practical pull-down self righting test on mine but it became the first boat the JOG NSW couldn't get down to 90 degrees (although heavier boats didn't need to be tested). The directional stability is excellent and I found the motion underway to be nice considering their light weight. At anchor they can roll in side swells because of the rounded sections. I bounced mine around on offshore races up to about 110 (?) miles and would take a good, well equipped one to Hobart quite happily.
With the small standard rig they are not particularly fast. To get the best out of them in terms of speed they need to be sailed with a lot of attention to trim and crew weight and then they sail away from other older boats like Compass 28s etc.
Mine's modified (different rig and rudder) and it was dramatically faster than standard, able to play with Peterson 30s, J/24s and the like and sail away from S&S 30s, Sonata 8s, East Coast 31s etc. Heaps of fun downwind offshore in a good breeze, when it would surf under excellent control.
They aren't huge down below but then again they are light and cheap for their LOA. The big coachroof makes access good and gives good interior light. It's a lovely size because you have standing headroom etc but the rigging loads and costs are light. We've now got a 36 footer of similar weight to length ratio and it's wonderful, but we sometimes miss the very light sheet loads on the Serendipity.
Most of them seem to be home finished and I've seen some layouts and fitouts that would send me running, but that's a very personal opinion.