[R-390] Seeking Advice: First Contract Number IF Deck

[Jacques Fortin]

Hi to all,

I do not know how much "First Contract Number" Collins R-390A (14214-PH-51)
are still in existence, but they came with an IF deck having no tuning
adjustments for the input / output of the mechanical filters.
Selected fixed capacitors values were used instead.
Does it worth to modify this deck to use trimmers, like in the following
versions ?
How can I be sure that the original fixed capacitor values originally
selected are still the right ones ?

73, Jacques, VE2JFE in Montreal