Auto hubs to Manual


Hi Guys
Replaced my original auto hubs with some off E-bay but still cannot get them to engage, drive shafts are just turning inside the hubs. Local guy has an earlier model for spares with manual hubs. When I looked at it has 5 allen screws fixing the hub to the wheel where mine with auto hubs has 6. My question is are the internals interchangable despite the different number of fixings? Can I just remove the circlip holding in place the internals and chance the manual parts into the casing with the 6 fixings as used in my auto hubs.Alternatively I may just weld up one set of hubs just to make 100% sure all other parts of the drive system are working, certainly everything apart from hubs seem to be fine.
Thanks for now.