S/B 1111 but it is not listed on the conversion chart: http://www.micro-trains.com/conversions/sheet001.pdf
1111 works well, but is a tedious installation... I dunno what kind of tips to give you, but really small, needle-nosed tweezers help a bit. Good luck! I have done a few of these on the Atlas cabeese, but even practice doesn't make it easier.
