Hi - Just wanted to throw my hat in here and post pictures of my C31 (Van Essen) - 1972, Hull #5. There aren't many here in the US but they do turn up. I'm currently refurbishing her bit by bit although she is in really solid shape.
Replaced the marine head with an AirHead composting toilet, rebuilt the head/shower area floors. This head is a good fit for the somewhat cramped compartment in the C31, and I'm happy with the choice. I am also replacing two of the large non opening port lights with Gebo opening hatches.
Complete paint job topside and bottom. Replaced the old barely functional front deck hatch with a Lewmar Ocean 30 (which was a near perfect fit - needed to shave about 1/4" off of the back edge of the opening.
She already has a basically brand new Yanmar 3YM20, 250 hours, and it's a great engine for this boat, size and power wise.
New suit of sails from Latell and Ailsworth in Deltaville, VA. I can highly, highly recommend them for folks in the US that want the services of a full hand made custom sail loft at fantastic prices.
All new running rigging. All new Dyneema lifelines. New Mantus M1 35 pound anchor and rode - it's too big, which means it just right, as far as anchors go.
Next I'll be replacing the original winches with Lewmar 30 self tailers which make her much easier to single hand.
I'll try to figure out how to make my photos of a size suitable for posting here and include them.