Yes, I did something similar a couple of years ago Darryl. Needed a new screen/security door. I measured it up fairly roughly, then toddled off to Bunnings for a door. I found they had both inch and metric versions, only a few mm different. I decided for no good reason that a 1970s house would probably have inch dimensions, and got that size door. Wrong of course. Now it's kind of a loose fit in the frame. Only large-calibre flies are completely excluded.
