I've dressed this and my other bars several times. They get that nasty edge on them as well wear. I typically use a right angle grinder, then a file checking with a small metal square. It sounds crude but has been very effective.

I may just take the chain in and have it re-cut, BUT that's about 6.00, so a combo is about 45.00.

I'll probably just give in and buy new, hang the old on a nail with the other one, and in 10 years wonder why I saved it.