A cracking fish and obviously huge. It looks a very long fish but with room to fill out. On my last stillwater chub campaign some years ago I caught a lot of "sixes" shaped like this. When I eventiually had a "seven" from this water it was far shorter and a lot deeper and more solid than any of the "sixes". I do know that the fish in my stillwater came from two different sources. If there are more chub in the Northampton water there could be an even bigger one there, especially if some of the fish are from another source.
Some familiar Throop chub there Neil. It is amazing how the shapes vary. Measured from the nose to the fork in the tail my Stour 8=8 (not from Throop) was 24.25" x 17.25". My mate Bill has had two eights from the Avon in the past which weighed 8-1 and 8-0. They were a different shape from mine and were both 23" x 17.5", both very solid fish. I remember the 7-15 Dave (Wally) Watkins caught and is shown in your picture. If I remember rightly it was a March 14th fish a few years ago. I was told the dimensions at the time but cannot remember them. It looks even shorter and deeper than Bill's two Avon fish, a real cracker.
As you mention in your post I am trying to catch a "six" during every month of this river season. My original target for the season was an Avon "seven" but as this was caught back in August I have changed my targets for the season to an Ouse "six" and a "six" every month of the season. I caught a "six" from the Claydon Brook the first time I ever fished it but my best Ouse fish is still the 5-13 I caught the first time I fished there some years ago. December is traditionally my worst month and I have never caught a December "six". I did find a group of large chub when I visited the Ouse a few weeks ago so I may be able to kill two birds with one stone if there is not too much more rain in the next few days. If I can catch one in December it will be almost job done as I often do well in January and my best two months are usually February and March.
The Northampton fish has tempted me to consider a local stillwater which has done chub to over 7lb. As they are not fished for much, as it is mainly a carp water, there may be bigger fish present than those that have been caught to date. If my local rivers remain out of sorts with the rain I will have a go for them. I feel this is a lucky water for me as I caught my pb perch of 4-3 from there the first time I ever fished there back in May.
I do hope the Nothampton fish is caught again as it obviously has some room to fill out and it would be interesting to see how big it can get.