leg room 30 roadster

[wbs]

hello my car could not be all original the bottom steering wheel to seat is only 6" the distance fr upper front edge of seat is 26" to a depressed clutch pedal. i put the seat platform[ called riser?] where prior holes were found. does the 6" seem too short and the 26" seem too long to you?

if so what modification should i make to correct? i made a side view sketch and attached it below