Language hat found the word adminicle recently (quoting Cassell Concise Dictionary):

bq. 1 an aid, support. 2 (Sc. Law) corroborative evidence, esp. of the contents of a missing document.
I particularly like the OED’s last citation:
1872 Daily News 2 Oct. 5 Floriculture and other adminicles of civilisation.

I seem to have lost one of my Scot law glossaries,but the Butterworths one has it (here’s the Lockerbie trial wordlist, which mentions both glossaries at the top – the Lockerbie trial was held in the Netherlands, part of which was declared Scottish soil for the duration, although they got by without the word adminicle):

‘adminicle – an item of helpful evidence’

That adds a lot, doesn’t it?

LATER NOTE: But I lie – of course the word was used in the Lockerbie trial (as a Google search on adminicles showed):

bq. 16 The conclusion regarding the presence of this
17 clothing within the suitcase containing the bomb then
18 becomes a fixed point around which all other adminicles
19 can be tested and examined.
20 And once it’s understood that the plot was of
21 Libyan origin, using the resources of the Libyan
22 Security Service, the conclusion relating to the bag
23 from KM 180 can be further fortified by other
24 adminicles of evidence.

However, I do think Shanghai United Food Additives Co. gets it wrong:

bq. So we can satisfy factories’ needs for kinds or quantity of food additives and special food adminicles and we can give clients much help on delivery, QC, payment and service.

It would also appear to be a Catalan word (like ‘Woddy Allen’).