I just finished a mast raising system on my Helsen 22'. It is 12v operated and is glass laid over my deck. When it is down, you can barely see it. This might be a little over the top, but take a look. You can see it on Youtube, just type in "mast stepping A frame" and you should reach it, also on my channel is a 12v operated keel, Bob.
I have a Helsen 20 and am interested in seeing what you built as I am starting to devise something for my boat. Any photos available?