I see two options for 68k machines.
1) Identify the browser as a mobile browser. While this won't give perfect access to everything, it may delay the inevitable by delivering page versions that have been designed for phones, and thus are lighter versions of the same site.
2) Use a VNC client to run the browser on the Linux server in the closet while delivering the screen to the Amiga. I'm doubting that there are many 100% Amiga users left, and the number of users with a server that could do the heavy lifting of the browser is only going up.
