hio77: Your on a naked connection, so logically the best solution is simply cat5e straight from ETP to your jackpoint, Use jelly crimps in the ETP ofcourse rather than than soldering iron!
Personally i would use a cat5 jackpoint - or even straight up crimp the end, using a RJ11 in the fritz's wan is rather ugly.
This would quite simply give you a clean line from the ETP, As mentioned it looks like a borderline connection but not everything quite lines up.
Would likely set you back a fair bit less than paying for a Master filter!
Always a chance your line will simply still have a fair bit of crosstalk on it though..
Cheers, I will look at getting some crimps tomorrow. A bit late/rainy/dark to do it now haha. If you don't mind me asking, do you work for a telco/service provider or are you just into this stuff?