The cheap day return fares are completely pointless though as a travelcard
would be cheaper. So the actual price would be £4.90 for CJ-FP and £6..30 for
Orp-WH.

Clapham Junction - Finsbury Park should really be £4.30 - a Z2-6 ODTC
(CJ to Highbury and Islington - perhaps changing at Willesden X, then
Victoria Line)

Thinking about this, rolling out PAYG on to NR services will cause all
manner of "valid route" confusion in terms of zones crossed: I know
this has been discussed before with respect to *some* tube routes, but
there would be far greater potential for dispute with the orbital rail
services, even as they are at the moment (let alone in 5 years, if the
current plans are realised).

For instance: Richmond to Maida Vale (do you have to go through Z1)?

Jase