The TOK idenity issue keeps confusing all.
A few facts....According to factory build sheets a Mr Lawrence took delivery of a hi-line SS chassis 4840, engine no 2537HR in June 1961.This can be verified by Ken Hills book 'Completely Morgan. Four wheelers 1936 to 1968'published by Veloce 1994.
It would almost certainly have been delivered with the 1991cc motor(more on that later) as were most hi-line cars.It was the 5th SS built/delivered and the 2nd rhd.
Because of Mr Lawrences wish to succeed in the 1962 race he felt it should have a low line body(less drag) as per the current 4/4 model. Peter Morgan always preferred the hi body and was not keen to change it but CL 'obtained' a low line body and the rest is history...as it turned out Peter Morgan was requested by buyers of the SS after the 62 Le Mans to build all cars from then on with the low-line...Im sure the 4 seaters(5) retained the hi-line until end of production in 1968.
So the car listed in the Silverstone auction this Friday maybe very kosher but it does not have its original engine as the class Morgan won in 1962 was the under 2000cc class and it would(should..or who checked?)have run the 1991 engine.
Other posters comments on what really is TOK 258 or how many TOK 258's are there is a very contentous proposition.
Maybe Herman Pol should give his view.
I own chassis 4749 the first SS built.