Since Tumblr appears to be incapable of sending me a password reset email it appears that both Fuckyeahbritisholdschoolgaming and Buildadungeonfrom me are dead now. No more updates unless two dozen password reset emails all arrive at some point in the near future.
HA HA DISREGARD THAT I COOK SOCKS
Later edit - couple of days later and the username/password combo I typed in two dozen fucking times suddenly springs back into life. No password reset email ever turned up so I suspect Tumblr have fixed something behind the scenes.