I spent the entire summer (in public too) in a tank shirt with armholes that left the most obvious part of my scars, the big drain knots, out in the open. Also, people who come to my house, deliverymen, people doing work, people lost, other random folks, are likely to see my chest because I don't tend to close my shirt or put one on if somebody rolls up unexpectedly. Sometimes I reckon I'd say I was mauled by a bear or something, but I have never once been asked. I have gotten sad looks, though. A fencing contractor last month looked very sorry about it.
Where I live, if anybody recognized the scars, I'd just about fall over with surprise. But it's a small place and having grown up here, I have no hope of real stealth anyway, so it wouldn't be a crisis to be outed.