I'm not sure if you'll find one in a junkyard over there,but you never know......
An early Austin Mini heater is a small self contained unit with demister hook-ups.
As you can see on the listing it won't break the bank!
That's what I'll be fitting in my '50,as no one over here can rebuild my original core.
You might find one a bit closer to home on ebay/craiglist etc.
Good luck!

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.