I think Kilydd is correct in his estimation of ~tonness; it may help that looking at my Fronsky I perceive that the Central line must be avoided for at least the first two plays. I must say it was remarkably optimistic of Stanley-Smythe to even attempt initiation using the at-the-time super-foetal Beckton - the DLR being in the mid C19 a concept "beyond the imaginings of mere mortals" as Conan Doyle once referred to future line play.
By my calculations the only TON stations (excluding ghosts) on the network are :

1. ALPERTON
2. BECKTON
3. BRIXTON
4. EASTACTON*
5. EUSTON
6. HIGHBURY & ISLINGTON
7. HIGH STREET KENSINGTON
8. KENNINGTON
9. KENTON
10. LEYTON*
11. LOUGHTON*
12. NORTH ACTON*
13. PADDINGTON
14. SOUTH KENSINGTON
15. SOUTH KENTON
16. WEST ACTON*
17. WEST BROMPTON
18. WEST KENSINGTON

Then of course there is MORNINGTON CRESCENT itself - but that is hardly going to be the starting station.

Finally there are two stations on the North London Line namely

• HOMERTON
• SOUTH ACTON

But it would be a strange ruleset indeed that allowed initiation from the N.L.L.
The stations marked * above are on the Central Line and are therefore excluded by my Fronsky calculations.
I hope this little exercise will be of help.

Oh, and considering that the (move=0) station is Alperton then the (move=1) station is not likely to be a doubling move either. If Beckton has been ruled out by Stanley-Smythe as reported, then that only leaves eleven possible stations by my reckoning - and Euston would seem highly improbable too. What d'you reckon folks ?

Presumably this assumes a theoretically stable level of play (LV and snoods stable, escalators and lifts dormant, etc.)?

Valid point Artaud, initial formulas have found that we do require non-zero LV for the (move=1) station, and we will somehow need to equate these cofactors into the Fronsky calculations already mentioned by Blob.
The analysis by Blob is showing that the next move in avoiding the Circle line has put a strong emphasis on 'allowance of linear movement' so I agree Euston is unwise. My own extrapolations suggest we should focus on either Leyton or Loughton thus avoiding divisibile cardinal notation.

Let me power up my Sinclair ZX81...