Mike. I have a copy of plans for 52-02 Sir William Arnold, which Neil kindly lent to me so that I could photo copy them and I am in the process of building her? It is not just the cabin which was different, the foredeck is slightly longer to allow for the shape of the front of the cabin?
If your son wants a copy of the plans, pm me your address, I will get them copied and send them on to you for a donation to the RNLI to cover costs.
Graham