S or T stocks have never been special order. Perhaps he means that the gunshop had to order it for him?
The T stock was fitted to all HW100's in 2003 and 2004. At the start of 2005, the first S stocks appeared. Both were always priced the same.
FAC airguns sell for quite a lot less than 12ftlb guns. 12ftlb seem to go for about 65% of new price. FAC would be about half of new price.
Here is a rough history of the HW100.
HW100's made in 2003 through to mid-2004 had the weaker cylinder threads and the inferior silencer. There were some grumbles about the trigger positioning. They all had T stocks.
I call them mk1.
In mid-2004, the silencer was upgraded to the highly regarded version we all know - with 1/2" UNF thread. Trigger was also improved.
I call these versions mk1.5.
At the very start of 2005, the S stock arrived.
In early 2005, the metal trigger blade was replaced by plastic.
Around mid-2005, the weak cylinder threads were replaced by a reinforced thread.
I call this version mk2.
In autumn 2006, the quickfill arrived, but not yet fitted with AT.
I call these versions mk2.5.
In Autumn 2006, the carbine arrived - all with QF as standard, but also all fitted with AT.
I call these versions mk3.
In early 2007, AT began to be fitted to the S and T full length versions.
HW100TK.177;Lightstream 4-14x44FFP. HW100TK.22:NVRS-F+doubler. Rapid mk1 .20:Lightstream 4-14x44FFP. SLR98.22:SR6NE 3-12x50IR.
Evo-T.177:SR6 3-12x44. Evo.25:SR6 3-12x44. TXHC.20:Falcon 4-14x44FFP. TXHC.25;WTC 1-5x20.