Unstuck hammer felts

[David Boyce]

Hello folks,
 
I've been lurking for a long time.  I'd appreciate any advice about re-attaching the unstuck and "sprung" lower side hammer felt on four treble hammers on a 1955 Kemble Minx (spinet type) 
piano friends of mine just bought.  There is just about room to get some clamps in, but I really don't fancy spending the time taking the dropped action out of the piano.
 
Sugestions gratefully received on glue etc.
 
Best regards,
 
David.