My club uses a very old-school marine railway for hauling and launching, and requires cradles for winter storage. JOWI folding steel cradles have been made in North Carolina and shipped all over the country for several decades. The company was sold to a new owner maybe 12 years ago, and I'm not sure if they're still in business.
If they aren't in business any more I would strongly recommend looking at their design, refined over many years, and make absolutely positively sure that whatever cradle you end up acquiring or having fabricated will fit properly at every step of the trip into and out of the water. For example, the design that Gareth's shop seems to use for their folding cradles wouldn't work at our club because the horizontal athwardship beams at keel level would prevent the cradle from being positioned under the boat when it's in the sling during haulout, and would prevent the boat from floating off the cradle at launch. Also keep in mind that the folding design (the stanchions can easily swing down) makes a lot of difference, because once collapsed its volume is reduced by 90% and it can be stacked on top of other folding cradles. They are all of course impressively heavy and require a forklift to move about the yard.
I accidentally bought a brand-spanking new JOWI cradle that was perfect in every way except that it was two inches too wide for our rail car, making it 100% useless. I lucked into a used cradle that another club member no longer needed, but the new one lingered like a steel albatross at my club for years and I happily took a bath on the price when a new Ericson 32 owner, who I think has since moved to another boat, found my advertisement here and drove it to Rochester.
My guess for an E27 is that you'll need a design with just four stanchions. If you're in salt water, consider a cradle made of galvanized steel. The mild steel cradles seem to start noticeably corroding from the inside out, and from the bottom up, after about 15 years. Mine had the lower beams replaced about 4 years ago by a local welder, and the upper beams are probably in need of replacement now.
