Mountfield M28M blade sharpening..Any tips?

[Brett2021]

I managed to remove this blade but the shape cutting edge is bit unconventional. See photos

its not like a sharpened knife's edge shape, where sharpened from both edges and central we have edge used for cutting . but here it is slanted rectangular shaped edge..

I tried to sharpen it with Angle Grinder, but not sure it really made any difference. Any tips on this..?

see photos.

 

[lostinthelight]

It's a perfectly conventional blade that is excessively worn. When the leading outer edge is rounded as much yours is it really needs replacing