QUOTE (Cynic @ May 2 2009, 05:44 AM)

... would give further opportunities for building up a pedal organ by extension - for instance, add 24 quite small pipes and a pedal organ of one stop becomes a (vastly more effective) division of 5 - acoustic 32' 16' 8' 5.1/3' 4'!
Cynic's advice is good, as ever. Do try Derrick Carrington of the Rendundant Organ Rehousing company. He's not far from your part of the world either.
However, I would take issue with the advice above and suggest at least a modicum of restraint. I've come across a small Willis organ where the pedal division was a lone Bourdon, later expanded in this manner - and it had more stops than the rest of the organ put together. Did it make the pedal organ vastly more effective? No, it didn't - it merely made the entire organ ridiculous.
What use is a 5 1/3 stop on a pedal organ - especially if the organ is small? Isn't a 32' bass derived from 1 stop quinted on itself a ghastly and ugly sound - especially if the stop is Victorian and of vast scale in the bottom octave? Why not just play down the octave at times and - if you must - use other (more effective) tricks for 32' effects?
A Victorian Bourdon extended upwards will make a fairly non-descript (although heavily used) 8' Bass Flute and (without fail, in my experience) an infrequently used, 3rd rate 4' flute. What are you going to use this 4' for? Because at best it'll do nothing, at worst, it'll stick out like a sore thumb in the sound of the rest of the organ. Will it provide an independent pedal? No, it won't because the flute based pedal extension chorus won't balance happily or sit comfortably with the principal-based manual chorus. Will you be able to play 4' chorale tunes in Bach Chorale Preludes? I doubt it... Again, for trio sonatas, would not all but the most dogmatic neo-classicist find it an acceptable compromise to couple the RH manual to the pedal for the pedal to have more definition?
Why not leave it to the ingenuity of the organist to extract as much versatility out of the organ at his disposal? If we start to modify organs in this way, do we not rob them of their character and disfigure them into something artistically deformed, into a shape they were never intended?
Were not the Orcs in LOTR once elves, tortured and disfigured into their ghastly shape? When I come across a much rebuilt or modified organ, I experience the same sense of revulsion and loss.
My experience is that I've gone from an organ with 8 pedal stops to an organ with 3 - and the organ with 3 pedal stops is so vastly finer than the old organ I've not once missed the 5 less pedal stops (including 4 foots and acoustic 32s - the 5 1/3 had disappeared in the 1980s). This pedal organ does everything it needs to because the overall concept of the organ and its design are strong and well thought out. The pedal organ's role is clear in this organ so the organist never feels a sense of compromise or inadequacy. In fact, when you hear the organ or look inside it, compromise is the word furthest from your lips.