68, yes, but wasn't the 88 a planned but never built freight version of the 87? I was thinking more of the 70.
This is a different locomotive, as that TOPS number has been re-used. It's basically a dual-mode version of the Class 68 in use with DRS, and the operator of this new Class 88 is... DRS! Modelling the 88 should be easy, as it shares many components with its diesel powered stablemate.
I do agree with you there, the Class 70 would be a good addition to Simutrans as a modern vehicle-plenty of oomph, and very modern.
Would be cool to see a dual power locomotive in Simutrans (i.e. Class 73, Class 88), but I guess the coding doesn't support the actual use of that feature.