Seabridge supply Sealine parts and what an excellent service I've just received.
I needed a new door catch for my Sealine and this company had it in stock and delivered within 24hours and the price was very reasonable (£14 for 2 catches inc. postage).
Speaking to the guy this is a new company dedicated to boat parts, mainly Sealine but he is looking to cover other boats. The website is under construction: http://www.seabridge-marine.com
Just wanted to mention it in case any of you are looking for factory parts and a good service.