Both
Kobo US and
Amazon US have the 25th George Gently adventure
Gently to a Sleep $4.99
Two more are available for pre-order at Kobo, on December 31, 2034 [
sic]
good old Kobo!
Gently Between Tides $8.09
Gently Heartbroken $8.09
No sign of any of these on Amazon UK, and Amazon US does not show the pre-order ones as yet.