I would just like to assure a few of the posters here that the Red Pudding is very much alive and well with thousands of them being consumed in Scotland each week.
A red pudding is a very different product to a saveloy in as much as meat is not the main ingredient but rather flour and rusk. This is what gives it it's lovely fluffy texture and the meats (bacon and beef) along with the seasonings give it's flavour.
It can be found in butchers and fish shops in the Tayside and Fife areas as well as chip shops throughout the East of Scotland. I should say that this is north of Edinburgh.
On the question of the casings it is to be found in 2 main types, namely betan which is red in colour for retail sale and clear cellulose for chip shop trade. There are also a very small number of retailers supplied with the product in natural sheep gut casings.
Although this is very much a local product it's sales in some areas make it the third most popular product in certain chip shops behind fish and white puddings.
I would also like to thank the lady whose story of her husband colouring a white pudding had me in stiches