I didn't recognize the machine, tho I think I figured that it was bcs we have another cross fandom fic coming up, but like others I leapt to the conclusion it's the 6th Doctor.
Time will tell.
(But then again, time can be rewritten, and go all wibbly wobbley on you, so you can't trust time's telling on that either. )
I know Rich won't include Evelyn the history professor (I posted that and on my computer, my post sat there without Rich's before it, next day Rich posted how he doesnt include audio and appeared before my post! Weird but true <g>) -but ... I admit I would have loved to see another adventure with her. Spinsterish, but far from infirm, she was the perfect foil for the Colin's Doctor's bluster, matching it with her own firm opinion, and then softening him up by promising to make him another of her delicious chocolate cakes or feed him hot cocoa with the chocolate melted in.
He'd hardly be able to say no to a request to take her along to Elizabethan era with that bribe <g> and who'd blame him?