Yes sorry Neil, I didn't mean to confuse anyone.
To a large extent my tools reflect the commercial availability of "stuff" over the years – which I think we've discussed before. So folk like myself who been going a while have probably 'evolved' their tooling over time.
My first collet blocks were 5C ones (all you could get back then) and I just purchased a few 5C collets to use with them. Then (I think) came a 5C Spin Indexer, to which I later added a 'Stevenson' ER32 adaptor – which resulted in my selling my 'Chinese' MT2 collet set – and purchasing a full set of ER32 collets. This was fairly rapidly followed by several ER32 collet chucks (for both lathes).
When Arc brought out their 'JS' ER32 collet blocks – they were an obvious thing to add to my ER32 collection. So I've still got both the 5C & ER32 collet blocks and it's sometimes useful to have them all (in truth I don't really like selling stuff either – nasty case of tool hoarding I'm afraid)..
However, if starting over now – I'd just buy the ER blocks (ER32 in my case but others prefer ER25)…
BTW – I also use ER16 collets/spindles for some work – and would probably buy ER16 blocks if they were available – although I could probably make some simple 'block' style accessories given that I've got the spindles….
Regards,
IanT