B+W 805S

I’d try one of the options below. All 8 ohm. Historically the HTM4 and 805 are the same but different form factor despite the different part number.

They look like a straight fit, except maybe the D2 with a little chiseling. The newer models should have a lower extension. Worst case, resell it.

HTM4S LF00235 $228.95

https://encompass.com/item/12593457/Bowers__Wilkins/LF00235/

805D4 LF27502 $276.95

https://encompass.com/item/13055678/Bowers__Wilkins/LF27502/

805D2 LF02336 $228.95

https://encompass.com/item/12593460/Bowers__Wilkins/LF02336/

Thank you everyone for your input. I believe the LF00235 is the best fit , should drop in with no modifications.

The port tube for the HTM4S is the same part so it should be a quick plug n play.

https://encompass.com/item/12591972/Bowers__Wilkins/PP25488/