You are making a lot of assumptions here:
Who made the claim that Jeremy hid the moderator in the gun cupboard? It is in the right place for it to be found.
Have you read Ann Eaton's statements in full? I haven't as yet but I find there were others present when Jeremy is making statements, so the question of the moderator may have been raised and at least 4 others were hearing what Jeremy's answers were.
Ann Eaton even made notes about what Jeremy was saying in his statement. So no doubt she discussed her notes later with David her brother and Anthony her cousin (??).
They all went and searched for this item later, when it should have been the police's role to do so.
In the book "Blood Relations: The Definitive Account of Jeremy Bamber and the White House ...
By Roger Wilkes" he writes that Anony Pargeter had used that gun and set the sights on it. He knew it had a moderator and telescopic sights as well and where it was kept.
It’s YOU who’s making assumptions!
You’ve no idea what was said on that first day!
You’re ASSUMING. Wrongly too.
No-one went looking for the moderator straight after Jeremy spoke to the police on the FIRST day!
They didn’t even GO looking for the moderator WEEKS later when it was found by chance.
Jeremy had tucked it away in a box at the very back of the gun cupboard — so why would he have done that, eh? THINK about it.
Forensics also PROVED the blood spatter from Sheila INSIDE the moderator was SPATTER. IT would be impossible to replicate that pattern. It was also impossible for anyone to have known what blood group was Sheila’s, and as there was no blood left in the house no-one could have got a liquid sample of her blood and replicated the spatter pattern.
This was all proved 35 years ago!