Many thanks Pakeboi. I've been through this list and can comment as follows:
1) Want to keep the chainguard as I cycle in suit trousers everyday.
2) Bike didn't come with wheel reflectors
3) Rear reflector: Will have to look into this, could be a cheap way of reducing weight, I may even have something suitable at home.
4) I already have the S grips
5) Tempted to change the wheels but all the wheels I have looked at so far have a fairly low rider weight limit and sometimes I am cycling with a laptop and a heavy rucksack
6) Inner tubes, changed already
7) See 5
8) Will see if I can find titanium mudguard stay bolts as don't want any aluminium bolts on the bike
9) Hinge clamp bolts: Titanium ones on order
10) Seat post clamp: Titanium one fitted
11) Tyres: To ensure puncture resistance I have actually fitted heavier tyres!
12) Stem expander bolt: Fitted titanium version which was part of a bolt set I bought
13) Headset: S type already fitted
14) Bike is the titanium version so already has a titanium front fork
15) Folding pedal bolt: Something I still need to buy
16) Mudguard stays: Something I hadn't thought of
17) Bike is the titanium version so already has a titanium rear frame
18) I have "upgraded" to the Firm Brompton suspension rubber. Is there a firm alternative which is noticeably lighter?
19) Titatnium seat pillar / post fitted
20) Titanium crank bolts are something I still need to buy
21) Bottom Bracket. Now this is an interesting area. I am very tempted to buy the Aceoffix bottom bracket that is available on ebay (sorry I can't post links as I am too new a member) or the Token bottom bracket that is available on ebay (sorry I can't post links as I am too new a member) The Token version is listed as 118mm so presumably not quite right given I believe it should be 119mm? Do any of you have experience of after market lighter bottom brackets? Any recommendations / comments? Note I have also seen the Ti parts one but at close to £200 I cannot justify it.
22) Handlebar catch bolt: Fitted titanium version which was part of a bolt set I bought
23) Rear roller bolts: Haven't seen anywhere selling these
24) Lighter saddle already fitted
25) Don't think a lighter chain will be good for reliability especially as the weight saving is likely to be minimal
26) I have seen some lighter cranks. Does anyone have any experience? I've seen a few on ebay (sorry I can't post links as I am too new a member)
I look forward to your replies.