Interestingly I discovered another type of PAL video today.
A DVD extra I was converting was originally 24p, but converted to 25i by adding 1 duplicate frame per second and then interlacing.
I won't be adding it to the guide since it was a bit of a mess and I don't know how often they actually pop up like this.
My script was:
telecide(guide=2).fdecimate(rate=23.976)
It's not perfect, there were some interlace artifacts left behind, but I can't think of a better way to do it.