Hi Mr. Yuri,

re:
> It would be faster to recreate whole model...

On a simple part that can be a good approach.

- Michael

Or another way:

Delete:


Extrude:


Draw a line across:


Construct > Planar to build a planar bottom:


Select the main piece, the extrude, and the planar bottom and do one boolean union:


The little triangle pieces will be cut away and left over.

- Michael

Maybe the thing that's blocking you is if you're trying to fill in just the very localized area around the chamfer itself. Like if you're trying to build just the smallest size patch that sort of fills in only what the chamfer removed.

You don't want to do it that way - instead it's usually better to delete both the chamfer and also the adjacent surfaces to it and then reconstruct the larger area.

- Michael

I believe that this little thing at some place blocks all your try! ;)
If you kill them and reconstruct faces by a simple loft by an edge all will be more easy



And i will make this : A little sweep by 2 rails + final bolean union