I seem to recall that the ends on my 1960 Harry Quinn track bike had "notches" to facilitate the use of adjusters. Never used them myself as unlike Ted I wasn't strong enough to pull a wheel over. Incidentally isn't rearward facing drop out a misnomer? I thought a drop out was so named because when you slackened the nuts or quick release, lifted up the bike the wheel "dropped out" which doesn't happen with track ends.