Thanks guys for all the replies

Even though I have stiffened my bags I think that the easy brackets are a non-runner, looks like I will stick with the PITA allen bolts for now and do some more thinking maybe some M6 thumb screws and go with jhortons suggestion (I don't fancy the wings of wingnuts catching stuff inside the bags) or maybe some thumb nuts or get a friendly machinist to make me some.
Ultimately I will probably buy some leatherlyke bags it is just a pity that the shipping from the US is so expensive

plus I need to top the bank account up after the cost of the rebuild and registration here.
Thanks again everyone.