Update.
I've just had my FEO pop over and deliver my FAC only a few weeks after I last spoke to him. I'm pleased to report that the resulting ticket is open.
What Lessons Identified can I bring to the forum?
Firstly, people on here are hugely useful. The Stalking community is relatively small in real terms and people here have a wealth of experience to share. If someone hadn't shown me, for example, the note on mentoring that could have been a real threat.
Secondly, make the FEO's life simple and engage with him/her. Mine had MAYBE made the assumption that as my good lady stalked I was hanging on her coat-tails. It's up to you to prove your credentials in a sensible way. Write down everything you bring to the party then when they present their argument up their chain of command, they have a positive feeling about your experience. I wrote my "shooting cv" in the third person so he could, in effect, present it as his own. I also included every single piece of evidence I could find namely:
RCO certificate
Previous open FAC
Safe Shooter card
Rifle club memberships
Letters of reference from professional stalkers
DSC1
I acknowledge that this is more than "should be necessary" but as (I believe) there is no appeals process against restrictive clauses then it's worth doing in the strive for an open ticket.
Thirdly, and perhaps controversially, I did my DSC1. I as stated in my OP, I did some equivalent or so back in the 90s but lost the paperwork. While my local constabulary doesn't hold the certificate in high regard it demonstrated that I was serious enough to "bring my experience up to date". I think the key thing here was I showed willing; that seemed to be of value to them. If you don't then be prepared to demonstrate the elements in some other way.
Finally, as I'm sharing rifles with the Mrs, they need me to vary my ticket when she (or in reality - I) buy them. This may seem a little knee-jerk but to have two people with the same slots may lead to doubling up of rifles. I get that and actually I think that's perfectly appropriate. Whether that means I will pay additional variation fees I deliberately didn't ask. I don't actually have a particular issue with that. Yes, a decent legal draftsman could have produced a caveat on the ticket but does that mean that every RFD would have noticed it and do they have someone that could write it?
That's my key takeways but what is my view of what the police were trying to avoid...
1. An open ticket immediately post DSC1.
2. They have generic concerns about people with limited experience or with range-only experience out stalking alone. Hard, from a public interest perspective, to ignore their point on that one (I appreciate that re-opens the whole mentoring can of worms).
Would it be easier if there was defined and acknowledged guidance publicly available. Of course but that it for another thread(S).
Thanks again for all the advice and support on this thread. It's been hugely useful!!
Right time to book some stalking!!!!