Having searched for our local scrapyards on line none of them offer online services. The ones that do don't seem to list "Morris" amongst the makes of car. All I can suggest is you trawl the internet and see if you can find one. Most yards now won't even let you in to look under the EEC Health & Safety regs. You ask and they go and look.
Are you looking for Minor spares or parts for other cars?
Some of the on-line Minor parts suppliers have quantities of second hand spares for sale. Try sending them an e-mail to let them know what you are looking for as they might have it in stock. Alternatively ebay offers the service you need - you just have to keep watching until the part you want comes up!
I've been looking for some itsy bits for ages but no luck, maybe not ages but every day I'm not getting nearer to the finish line because of these parts!