Is there a way of telling whether a D&N (or clone) is chipped or not before playing? It's just that I've got a refill key on the way and I've spotted a Doctors 'n' Nurses (30p play, £25 JPT) in a rural pub that is in a quiet games room with no CCTV or pub staff watching. Don't normally like Extremes, but this sounds like the ideal candidate to attempt the MTR on. Looks like its been there for a while, so I suspect it may not have been chipped.
Another question, when you turn the key after getting a 'trail held' above 4, do you need to remove the key once on the board?
If its a location where the staff dont come round glass-collecting too often, i tend to leave the key in, as the sound of the key being inserted/taken out can be what gets you detected in a quiet place.
I think the reels are different on different extreme machines. On RTB, the number 1 on the third reel which you need to nudge in is on the orange and is either 2 or 3 nudges away from the plumb with the red box. I had a mini go on Most Daunting and found that the number one was on the strawberry and had different symbols above and below it to RTB.