I had a problem getting my spitfire pump to work, a second non return valve after the pump sorted it out. The bellows is just a rubber bag, unless leaking there is nothing to fail, but then it started to leak but early spit ones are available
Yes overrider bracket. There should be a metal tube and a long bolt which hold the top of the rear overrider on the low bumper cars
https://www.canleyclassics.com/?catalogue=triumph-gt6-mki/ii&diagram=triumph-gt6-mki/ii-bumpers-mki
The colour of coolant doesn't mean much at all any more, some can be had in multiple colours so you really have to go by the chemistry. Penrite do a blue longlife OAT https://penriteclassicoils.co.uk/product/7-year-blue-coolant-anti-freeze-premix/#:~:text=Penrite 8-Year Blue Coolant,degredation of the cooling system. but it can also be pink green etc depending on manufacturer
If you replaced the throttle disks it is very easy for them to not be perfectly centred and so allow air around the edges, If you hold the carb up to the light and can see any light around the disk it is not centred
the endfloat is basically how much the drive gear can move up and down with the pedestal fitted. You adjust the number and thickness of gaskets to set this movement. The Haynes way gets you to measure the gap with no gaskets if that is say 10 thou then you need to add 15 thou of gaskets to get 5 thou endfloat, they get you to measure by cutting a notch out of the gaskets so you can get a feeler in to measure the now 15 thou gap
you could also use a dial gauge and a strong magnet to pull the drive gear up to measure endfloat and just adjust the number of gaskets until correct
Probably won't help but I set the endfloat when I had the sump off (complete rebuild) with a dial gauge on the top of the drive gear and then pushed up on the oil pump drive from underneath. Very simple but not helpful if the engine is complete
The bottom line is the factory specs are for what the endfloat should be at rebuild. This will of course increase with wear and after some time will be out of factory tolerance, but factory tolerance is for a new engine, so yes if I have the engine in bits I would set within factory specs but on an older engine a few thou outside is to be expected
there is 2 on ebay at the mo. They do have the TR tax though!
https://www.ebay.co.uk/itm/404795454038?itmmeta=01HPPTSJ8FDMMJ2P07CGYPCBCS&hash=item5e3fb07256:g:mHcAAOSwk0tlV53b&itmprp=enc%3AAQAIAAAA0Gb9LHOOxo%2FLwvAy1YdL01AeHeX2Y%2Fs%2Fp6t8KlNKqU2x8udeWSIiwdmySwRJBWXFT5Jv4A5JNCz7ac20prCdDZR%2FO6n5ollvlzhl4LrAxzulYnU2%2F3rc41A4OPunxeEqaBpZAodOewfdwimFdJnlQBrpoqbHOJzWtRlTDnWZEVrMJ9CuK%2FZ0bFbRyYPGHB81vz72Wtjdy8nsF2vsn1eD5oDifeS2A7J9MfNzYRnGAW6BviGDIZbi%2FqpjYoFyUiaLvdn6olAtjh9sLf2mCEKVJAc%3D|tkp%3ABk9SR6qk5tq1Yw
https://www.ebay.co.uk/itm/256276578620?itmmeta=01HPPTSJ8FKNJBY3B5CSQGWK5W&hash=item3bab46413c:g:XgUAAOSwiKFlQQRt&itmprp=enc%3AAQAIAAAA0I1IFH%2FlovHnYZwde53DItuHpcGdcyYW%2BWOiI1grFXRohhy%2BpYJ3ugmU5BQrDmGj3HXBVQvSF9CxD%2FjRZUIMBiAt6mD%2F82%2BBMEEIwd%2Bg0MnMyvm4FZ%2BT0Kp0g8nXvEOhAy8UqQfh8m8IfLERcNiJvR7TfsSFSi4HVfJYcBIbJld%2FoAvk2V%2BrRifm%2FZHrYAK6X3Fet2wd83TtCLtG0fnSQ73Fc0tBESX5Vt87Oc7T08CuBAyNAcfuuKTFMF%2FtP0dlYy8%2B7TqyJauiRBfCcV6mFb8%3D|tkp%3ABk9SR6qk5tq1Yw
It wouldn't be just the capping, the early frame would not have the holes with the catch in into which the later soft top catches fit
I also have a suspicion that the hardtop header rail bolt holes were at a different spacing on late cars to early so you need to check that the spacing of the mount holes in the frame matches the captive nut spacing on the hardtop of course if not you could use rivnuts on the hardtop
probably the aluminium push rod tubes, which are a pain to seal, oil leaks slowly and collects at the back. My mk2 spit did this but maybe not if the oil is collecting on thee rocker box as too high