It only take minimal effort
This the simplified fix for the Xover filters
Capacitors: Low pass: C1=40n, C2=20n, High Pass: C(ab)=4n7
LP HP HP LP HP HP
FREQ. Ra,Rb R1 R2
249 Hz 22K600 95K300 191K00
The manual and schematics for the unit can be down loaded.
These filters appear to be L-R so be aware the original 4350 card filters were not depending on the version see 5235 manual for details.
You will probably have to Eq the crossover region and mess with the polarity of the high pass amp to get it dead right
If Byston are so lazy (its the Canadian attitude ..trust me) then refer to a local technician. He will find the bump filter without much hastle and sort that.
The unit is too good to sell on.
Enjoy
Ian