Vn-vq are separate from vr-vs if you cross match them say hello to smoke and goodbye to cluster
yes the full cluster is not compatible, as i said earlier
the trip computer (inside the cluster, houses 3 lcd screens, aluminium housing, shitty white/beige plastic front) is compatible between all the models (except the earliest vn version that didn't have a chime and hates having 1 pluged into it) if you change it between suitable clusters, the trip computer has the same pinout between them all and is not wired into the cluster itself, i have run 88 vn, 92 vp and VS (can't tell you the date as i'm not pulling the dash apart to find the vdo sticker) in the same car and once speed and fuel consumption is calibrated they are accurate, without any wiring modification to the trip comps plug.
I posted rips of the microcontroller program from early vn, vp/vq and vr/vs clusters on another forum (i'm yet to find someone to rip the code apart and find out the exact differences, i suck with programming and coding, quite happy to hand the code over to anyone that can understand 8051 asm as there are some changes i'd love to incorporate into the lcd readouts eg. bugger off the speed alert and change it to digital speedo, possibly add tacho readout aswell as there is an input into the trip computer for engine rpm, change the fuel value to suit custom tanks like lpg instead of either 65/80L.... widen the cal range so it can be set to accurately display lpg L/100 etc etc....) ford at the same time had digital speedo, tacho and i'm sure the trip computer is capable of utilising these functions.
as the LCD's are getting hard to replace i'm currently looking to replace them with 8 segment LED displays, limited time for hobbies has proven to make this a slow process...........