1999 Steinway B hammer felt fraying?

[Bec and John]

Hi,

I tuned a Steinway B from 1999 (or 2000, can't remember the serial 
number exactly) today where the hammer felt was frayed quite 
noticeably. Of course to describe the the degree of it is subjective, 
but I've never seen anything like it.

Does anyone have any thoughts as to how this came to be? Not so hot 
felt, bad filing job?

Thanks.

- John