Topband: Inrad-Filter for TS-520?

[Martin]

Topbanders,
i recently bought an old Knwd TS-520S.
I am very surprised how well this rig hears, especially on topband.
The CW filter however is the stock knwd filter and leaks close spaced 
signals. I am very satisfied with Inrad-Filters in my other rig, a TS-850.
Inrad lists filters for the TS-520 as well on their website, but the 
shape factor is 2.7 ( 1.7 for the TS-850 filter).

What is the shape factor of the stock filter? Will a inrad filter
improve things or is it just a replacement for the stock filter?


-- 

73, Martin DM4iM