After reading the suggestions, I tried jxself's kernel. It resulted in the
ugly terminal boot screen being replaced by a nice Trisquel logo and
background, but it also killed my wi-fi access again, leaving me no way to
ask how to fix it.
So, I installed 6.01 instead. That's working fairly well, except for not
remembering how I got my Brother HL-2270DW working the last time.
All told, I'm more or less back to where I was a few months ago, which goes
to show I should have coughed up the money to order the wi-fi module back
then! :D
