yes you can buy new seals,but could be your hinges,lock or the windows need re-sealing with silicone so check first to see where the draught is coming from.If its coming from hinge side you prob need new hinges on windows of that age,just do a search for window hardware and a few will pop up or you can go to www.lockmaster.co.uk and should get some from them.hope this helps
shaun www.sdwupvcrepair.co.uk, January 2009