904 not shifting into gear

If it starts in park and engages into reverse when you select it that tells me the shift linkage is moving and probably closely adjusted but do like TB said about the linkage adjustment and let us know if that solves the no neutral start/no reverse lights problem. If it doesn't something isn't right inside where the rooster comb engages the switch and you'll have to drop the pan to check it out. No forward gears is quite possibly a torn lip seal on the rear clutch drum or they might have done something wrong installing the shift kit. Can you contact the guy that rebuilt it and talk to him to see if he ran into any possible problems during the rebuild that may be a hint as to why this happened?