I just pulled out my original copy-- yes, that's a typo and should be "fasten off".
As for the thumb increases, here's a translation:
1. In the first round where you increase for the thumb, you inc 1 in the first st [that's 2 sts], knit 1 [another 1 st] and then inc 1 in the next st [and that's also 2 sts]. That's a total of 5 sts you now have for what is going to be your thumb. Then you keep knitting for the rest of that round.
2. Now you knit 2 more rounds, just plain knitting, nothing special.
3. For the next round, which they call the "2nd increase rnd", you inc. 1 st in the first st [thats 2 sts], then K 3 [that's 3 sts], then inc. 1 st in the next st [that's 2 more sts], for a total of 7 sts in your thumb section, and then knit to the end of the round. THAT 3 I PUT IN BOLD IS ANOTHER ONE OF THEIR TYPOS-- it should be a 3, but they wrote "2"
Then, again,knit 2 more rounds plain, without doing anything special.
You're going to keep doing this, that is inc 1 in the first st, knit some sts in between-- each time being 2 more than the previous time-- and then inc 1 in the next st, until there are 15 sts in that thumb section. To make it even clearer: in the last increase round for this thumb section, you will inc 1 in first st, knit 11, then inc 1 in the next st. This will be 15. You will have a total of 54 sts.
As I said, I have the original from my grandmother, so don't hesitate to ask away. It seems that the copiers weren't completely careful!