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.
Actually, I think the engine in Chassis 4840 is the original engine. My 1961 Plus 4 Four-seater is Chassis 4850, only 10 chassis later. My engine number is TS82122ME. According to the auction publicity, the engine number for #4840 is TS32115HE, but I think the examiner misread 3 for 8 and H for M. If so, the actual number for the engine in #4840 is TS82115ME, which is seven numbers before mine. In those days TR engines were delivered in batches of about thirty and installed in no particular order. So these two engines were probably in the same batch -- TS82122ME went to chassis 4850 and has powered a four-seater around America, while TS82115ME went to chassis 4840 and LeMans glory.
The auction brochure lists the engine capacity as 2138cc (TR4 capacity) rather than 1991 cc (TR3 capacity). However, the engine number has the suffix "TS" which denotes a TR3 engine -- the TR4 engines have the suffix "CT". The obvious answer is that 4840's TR3 engine was rebuilt with a TR4 wet-liner set. My TR3 engine was rebuilt in 1971 with the TR4 liners, and it's impossible to tell without removing the cylinder head. Everyone who rebuilds a TR3 engine uses the TR4 liners, unless he wants to race in the under-2-liter class. I assume that 4840's engine was fitted with TR3 liners in the day it won the under-2-litre class, but has since been fitted with the larger TR4 liners to give it even more speed.