Stuart is right, books 3 & 4, they are not an expense, they are an investment.
You will however need to recognise that your SV Confortevole was a stop-gap model bridging the demise of the Lightweight Sprint Veloce production with the simplifying of the Sprint Model Line-Up, by blending the trim of a Sprint Normale, with the powertrain and mechanicals of a Sprint Veloce.
Basically the parts catalogue doesn't cover everything to do with your SVC, despite 149 being built, even less with mine being one of 50 with the framed wind-up windows.
Additionally remember that from the beginning of '58, all Sprints were fitted with 7" lights to meet the USA requirement for sealed beam headlights. FWIW, the latest Sprint chassis number with 6" lights I've found is 1493*5919, while the earliest with 7" lights is SVC 1493E*06046. the change happened sometime within these 127 chassis numbers