Vy.: Using an OMB5E on the 522 would be a bad idea anyway in my view, as that's not ideal for the ULM arm in terms of compliance. An OMB10 is hardly more expensive, but would already fit a good bit better to the arm - although for a 522 I'd suggest to go for higher quality and use at least an OMB20.
However, as you don't have the halfinch-mount adaptor kit (afaik, you'd need adaptor kit G - i.e. this one: http://svalander.se/vinyl/skal/3178_500.jpg
) yet anyway, an new DN145E for the ULM45E would probably be the most reasonable choice.
Greetings from Munich!
Manfred / lini