They were fairly good cabs at one time, check the surrounds for rotting, its a problem with some wharfedales.
You might not be able to get a schem, are you trying to repair one?, if so use the other to work out what you have, presuming the other speaker has a good xover.
I would like to find a spec sheet .... have one blown speaker ( mid range voice coil blown : cone and coil fozen and cannot move) and one questionable woofer .(cone& coil move but not really smooth as a new speaker should.) I may try experimenting with crossover points as well as adding a fuse assembly and possibly an L-pad on the tweeter. This model was really pleasant to listen to when they were new but have deteriorated over their 30yrs of use . The 510.2 models had a design flaw with drivers and tweeters being overloaded when driven at a higher volumes. I was hoping to correct this by altering the crossovers with a different frequency curve . If I can't get spec info . I guess I'll have to experiment! Thanks , BillyV