[old_tv_nut]

You have it basically correct. To clarify, the output of the video detector contains an FM sound carrier at 4.5 MHz (for NTSC system M). The video path then usually has a 4.5 MHz trap to prevent the 4.5 MHz carrier dots from appearing in the picture.

Here in the audio section,T5 and C20 (with C16) are a tuned circuit to select the 4.5 MHz carrier and attenuate video components. The amount of tuning obtained from C20 vs. C16 is hard to tell without knowing the output impedance of whatever L24U is connected to. So, at least C20 needs to be reduced and maybe C16 also, to tune this circuit to 5.5 MHz. Similarly, the capacitors inside the T3 can need to be reduced. Part of the problem is that the caps inside the T3 can may not be marked, so there could be a problem knowing what to substitute. C13 needs to be reduced also.

To match the original design parameters, the values of the inductors should be reduced also, but of course there is no information on their current value. Hopefully they can be retuned to lower inductance enough.

The resonant frequency of a tuned circuit is f = 1/(2*pi* (sqrt(L*C)), so to go from 4.5 MHz to 5.5 MHz, you want to reduce both the L and the C by the ratio of 4.5/5. = 0.82. So, C16 becomes 8 pF, C20 becomes 6 pF, and so on.

You might start by ignoring the capacitor changes and try tuning the inductors only, to see how well that works. If it doesn't work well, then you must look at changing the caps.

I don't know what the alignment procedure is in the service manual, but the procedure should work just as well for 5.5 MHz as for 4.5 MHz.