I'm guilty of using blades to long also.
I have purchased the USA sharpeners orbital rotaru cutter blade sharpener. I took it on a visit to daughters and we sharpened all our blades. well they are now like new and it really works. it will sharpen 45mm & 60 mm blades.
I haven't used the sharpened blades enough to get them dull again so I'm not sure how many times you can sharpen them but at least they are great the first time around.
kjym Kathy