Shell
I think your point was that you already know the SVR and this is high due to your husbands credit record.
In the circumstances, you should contact a local Independent Mortgage Broker and see if you can obtain a better rate. In regard to the inaccurate credit record issues, you will need to gauge how long this matter will take to resolve, when deciding whether to go for another fixed rate or a cheaper SVR elsewhere. Be careful to check any fees which tie you in for a period as you would be annoyed if the credit records issue was resolved in a few months, thus allowing a cheaper rate to be obtained.
The unbiased site may help you find a mortgage broker and the CML has guides which may be worth reading.
http://www.unbiased.co.uk/find-a-mortgage-adviser/
http://www.cml.org.uk/cml/consumers/guides
In regard to the credit record issue, have you thought about asking your local MP for help. If your MP wrote to the company concerned to make an inquiry, you might get the record corrected abit quicker. The problem of debt and credit reference agencies is on the political agenda at the moment, so they might be interested in helpling. My moto is that if you don't ask, you don't get. Also the election is only months away so they may be very keen.
If you are a bit embarased about contacting your MP, you could follow the advice on your previous thread. You need to write to the company (Hillsden?) that applied the wrong information. The links in conmankillers and basa48 posts contain links to sites that have advice/letters to follow. This will take longer than if your MP got involved. Believe me, having worked in financial services, if a company receives a letter from an MP, it is given priority and they will make sure they deal with it properly.
Huckster