Sounds good. -) I'd try talking them through various different approaches - obviously, content partnerships (with examples of pre-existing ones), but also things like us helping them with digitization of particularly important works (and/or proofreading for texts), Wikipedian in Residence, Backstage Pass-style events, putting curators in contact with wikipedia editors and generally sharing knowledge, getting them using Wikipedia content/links on their website/in their displays, etc. Don't focus too narrowly on one of these to start with, but see what they are interested in initially and then press on with that.
 Let me know if you need any 'official' representation or other support from WMUK, e.g. if you want me to come talk to them with you, if there is content that needs uploading in bulk, or agreements signing, etc. Also, if you need any financial support at any point, let us know - if under £100 then via the microgrants process, or if over then get in touch. Basically, if there's anything we can do to help, let us know. ;-)
 Good luck!