Lego set 6991 Space Police monorail

Having 'obtained' another space monorail set recently, I decided to buy this thru Ebay.
Both sets are from the mid 1990s, so are almost 20 years old but the motors work perfectly.
I hope to combine the 2 sets with the expansion pack I also have to create a 'super' monorail set.

I just need to get the Airport shuttle set and that would be all 3 monorail sets....