Great points Jerry
I shall take another look at not using the vinegar, it worked for me , but I am always up for any improvements or experiments to try, the chillis used were probably birds eye, they were short thin and green from the indian shop and were hotter than the longer chillis from there. Yes vindaloo definately has a greater depth of flavour , the dried red chillis gave a deeper flavour. I have tried Naga masala, naga chilli powder but none gave the flavour I was after.
This recipe did produce a belting vindaloo, and I am more than happy with the results from all the testing I did. I hope more people get time to try it and gave their feedback