Tobbeo said:
Sorry I can't be of assistance (no experience), but impossible?

Every frame is intact (well almost) and originally intended to run in 24fps. PAL just plays it erroneously fast, there must be authoring programs that can correct this and convert it to BD(24p). (or will converting distort it unacceptably?)

Anyway reason I want BD 24 is mostly the audio pitch-up of 25, but also why watch films incorrect when there's a choise.

NTSC-film uses 23,976fps which is the same as Blu-Ray. Although basicly everybody falsly states BD is 24p it's actually 23,976. NTSC DVDs can also be played in so called 24p if player & display support this.