I have a few complete P gearboxes, one of which has been Forderised which, if all else fails, might suit you. I would not want to part with just the case however, the whole thing would have to go. (numbered 752 165) E-mail me if you cannot find anything else.
Thanks for your reply. I am hoping that someone out there has just a casing I can purchase numbered 135 or 165. I have all the internals for an NB box and a very kind member has said that they will swap the NB numbered casing that they have for a P type one. My NB currently has an NA gearbox in it and I would like to make the car as original as possible.
Unfortunately the first casing that I sourced has been lost by Parcelforce.