Deist will manufacture to your requirements, I spoke to them on this exactly when I was there last year. All Ihad to do was email or fax them the desired measurements.http://deist.com/contact_us.html
Ph. 0011 1 818 240 7866, their fax is 240 7866
Make sure you get a postage quote before they send it over so you don't get a shock.
Hope this helps,
I owe, I owe, so off to work I go.