Instead of summarily declaring this as a failed project, I am going to proceed with bottling and then hide it in the garage to see what it does over the next couple of months. Being a five litre batch I stole from my proper Dark Rye Brew it is not a total loss as I have the other 15 liters to savour (I have tasted that and I am pretty happy with the result!).
Anyway, lets see how this turns out after a month in a bottle (which I will be doing soon after another tasting).