Trinity Ointment might well do the job of Tricycle Ointment. The latter is a lubricating and emollifying material for smoothing the axle of the Three Great Turnings of the Wheel of the Dharma; put more prosaically, it is an anti-haemorrhoid cream for monks who must spend many hours sitting in meditation.

Where might one see a Manchester Gallop?

Prefixing a Face Pyjama with the word Manchester traditionally coarsens the thing described. For example "I unscrewed it with a Manchester Spanner" means you used a Hammer. "I knocked it back into place with a Manchester Hammer" means you kicked it, and so on. So, a "Manchester Gallop" must mean one of those stumbling runs with random reels to one side or the other and frequent collisions with road furniture that are popularised by the consumers of Strong Drink.

Portsmouth Kettle

The use of the word Portsmouth in a Face Pyjama is very similar to the use of the word Manchester above. It is used to describe something that is unutterably dull. Obviously a Portsmouth Kettle either needs a good polish or lacks charisma.

But what are Budgerigar Trousers?

Ah ha! You have come to the right man for that information. Back in the Dark Ages, circa 1958, I was heavily involved in the breeding of those delightful little creatures - budgerigars, that is, not trousers. Actually I would have taken on trousers but, in those days, it was nearly impossible to get the zips mated. However, I digress.
The main aim of breeders at that time was to produce a bird which would 'drop it's daks' only for the right mate; it was considered that this would enable the use of multi-species aviaries without the risk of any cross-breed infections. To this end many, many experiments were undertaken and, sadly, in the interest of science, many birds perished. Eventually, being a leading light in this field, I was successful - to a degree anyway. Regrettably, whilst the finished product looked fine and theoretically should have worked, it didn't. It turned out that the male budgies were only 'turned on' when the female produced with the new genes was deceased. So, effectively, the breed died out after only one generation. It became obvious that, instead of producing a budgies gene rouser, I had inadvertently come up with a budgie rigor rouser. This was a spectacular failure which, to my chagrin, has gone down in the annals of the bird breeding community as a 'cheap and seedy' endeavour. Unfortunately it was also picked up by the popular press (in particular the "Parrot Breeders' Bible.") So, with it's wide circulation - and numerous typographical errors - the term which they coined has now entered the common vernacular. I'm sure that most of you would know the phrase (although some are more protected than others) which both sexes use in the pub when a particularly attractive specimen of the opposite sex is sighted wearing a well fitting pair of jeans?
Basically it means that s/he wouldn't be interested in you even if you were dead!

Leaving wild life to itself these days I am now more involved in the 'meaning of everything'. So when I came across an articulated case the other day, I was rather intrigued. Something to do with the law? A strange and mobile computer container? The title of a detective novel? Anybody know?

This is a doctor's discreet euphemism, when speaking in front of the patient, to signify that the patient has a screw loose, is unhinged, a leg short of a trivet, etc.

Speaking of trivets, or perhaps not, what is a trivet screw? I don't see it listed in Machinery's Handbook.