The problem I think is that as DV was about 11 in 1986, he wasn't in a position to gather evidence at the time. Therefore he can only work with whatever he can gather now, and what the police did gather at the time. The police do not look like plain dealers in their response to him because they dismiss anything he has surfaced now as unreliable because too long after the fact, while expressing no such reservation about 14-year-old TV-prompted hearsay that points to JC; and the evidence they say DV needs to produce is evidence they, not DV, should have gathered at the time themselves.
So essentially, they're dismissing what he has given them on the basis of one standard that they don't observe themselves, and on the basis of their own omissions 35 years ago, as though both of these somehow invalidate his thinking, but not their own. But they sought no witnesses as to SJL's movements in 1986, focusing entirely on placing her at 37SR. Witnesses such as BW, who despite this came forward with sightings that undermine this narrative, were simply dismissed or explained away - which is not the same as explained.
Consequently, the only way to establish now if SJL went to the PoW is to search it and see if she's still there. The police apparently think JC drank there, so that's their in, should they choose. At any rate it remains inexplicable that they were so incurious about what happened at the last place two witnesses said she was going. MH, the regular landlord, was not interviewed even though he was there that morning. He only found out a year later from the police that they had been, when they came back looking for CV. CV had not said a word. It could all be innocent, but that is weird.
You're clearly persuaded by the abduction hypothesis, and I certainly agree with you that it's a highly likely one and the the only real alternative. I differ maybe in that I am as unpersuaded as the CPS is of any JC involvement. The possibility she went to the PoW on the errand two people say she was running and that her colleagues knew about does not to me seem so outlandish it can just be ignored. I can't think why you'd search WJ's house, but not that pub.