Aaron, there should be 2 keys ( one ignition & doors, 1 boot & glove box) but that presumes no one has changed one of the locks in the past with one that doesn't match the original.
Do you have the key numbers? You may have trouble in geting replacements as the key numbers are not marked on the locks. There was a little tag supplied with the original keys that had the keys numbers but if you do not have that then your choice is either buy a whole used set of locks with matching keys (in fact some of the locks are still available new with the keys), or get a Heritage Certificate from British Motor Heritage in the UK which should give you the original key codes. Once you have the codes you can hunt around for someone to cut new keys to code for you.
Of course, with the latter method it is not foolproof because you may find that the locks are not original, so the original codes will be useless. May end up being simpler to buy a replacement set with keys.
Tony
<font size="1">1981 2L FHC Cavalry Blue - very original & not rusty!
1980 3.5L V8 DHC Regency Red - on the road again.</font id="size1">