Hi Norman, Yes and Yes are the answers you need I reckon. It’s worth checking if your mast bearing plate sticks proud above your deck. If so that distance will have to come off your measurement. If I were you I’d leave it fairly high untill you get to an event and then get someone to check it out. The way they measure it is generally at the same angle as the mast. As I say leave it high. Easier to cut than to glue!
Hope to see you at a few events this year especially if you have a new mast. You’ve got to now. It’s the law!