What can I do with this wooden patio door step?

[Scarum]

Hi

Following on from problems on the other side of the patio door (original screed to patio door poorly laid) I decided to start working on varnishing the exterior in this nice weather.

After removing old bubbling varnish I found numerous cracks on the wood (mahogany I think) and some well weathered wood coming away quite easily. The result is for all to see...








Can anyone advise if it's worth filling in these cracks before varnishing? Or would it be best to get the patio door frame replaced (or can I get the door step simply replaced?)

Thanks for looking

 

[God]

Assuming the rest of the frame is good, chisel off the old cill goto jewsons I think they may stock hardwood cill, grab a length drill and plug through the face of the cill and there you go one new cill