Terry, has your friend considered attending some of the many model railway shows on any weekend throughout the country. A scan through the Railway Modeller will unearth loads of exhibitions.
If your friend wants less "scale" and more fun then check out the many dates in any of the club journals. H.R.C.A., T.C.S., B.L.S. and G.O.G immediately spring to mind.
Claughton 1345s suggestion sounds like a good one to me.
Members in clubs and societies are generally very friendly and happy to chat at exhibitions.
When displaying myself I'm happy to chat to complete strangers but I might be reluctant to invite unknown folk into my home without getting to know them first. Not that I have anything to view at the moment. All Hornby and Middleton track has been lifted and is used on my "portable" 22' by 10' and other smaller layout. Once the Atlas track is down 38' by 12 1/2' with smaller alcoves for turntable and engine sheds with turning circle and storage sidings in the other will give a good sized layout. The proposed garden layout will have to wait it's turn and probably my retirement.
To summarise, try model railway shows, club nights and/or society events.