If you know there are aircraft landing in Liverpool or Manchester whose operators you'd like to speak to, then find the registrations (spotters' websites or blogs) and trace the operators. Really easy to do in 30 minutes as most operators have a website with contact details on.
Bear in mind that many ad-hoc cargo aircraft flying around Europe are not based in the country where many flights operate from/to. Some chase the work and don't bring the a/c and crews back to base for some time.