That does seem to be rather excessive. Do you have the kickstart ratchet assembled
correctly? It's this that controls the endfloat. Be careful with the nut on the mainshaft
as it hasn't many threads and once damaged it's a nightmare to repair.

Without measuring, the tank looks to be modified from a set of standard toolbox pressings.

Below should be the photos of the Mk1 oil tank:

hs_1.jpg

hs_2.jpg

hs_3.jpg

hs_4.jpg

hs_6.jpg

The filter bolt is the same as used on Square 4s Oil delivery filter bolt, 5861-37.
Mine came from ...

Hello Chris,

Like you I'm after a Mk1 air cleaner but I do have an oil tank waiting for when
the air cleaner finally tuns up.

Yes, the cap is a bayonet type and when I get a few minutes I'll post some pictures.

Welcome to the forum.

A standard VH wouldn't have had gaiters, they had metal shrouds.

Are you sure your front wheel is actually Ariel? A photo would be a help here.
The bearings in an Ariel hub are both ball journals with the one on the brake
side having an internal sleeve. Both are available ...

The supply is the one nearer the middle.

Unless you plan to ride it most days some sort of anti-draindown valve will be a necessity.

Mine has an automatic valve which seems to work well enough which was fitted by a previous owner
so I don't know for sure who made it. I'm no fan of taps in oil ...

There is a 'Forum Help' section which is useful and particularly

viewtopic.php?t=193

which details adding images. Don't worry if the images appear
on their side or upside down - sometimes they do that.

Welcome to the forum and the club.

It sounds as if the part you seek is the rocker box feed pipe which may be available from Draganfly

https://draganfly.co.uk/product-category/ariel/ariel-4-stroke/

Later twins suffered from over-oiling of the rocker box and a common modification was to take the ...

Welcome to the forum John.

It would help to know what bike you want the shells for.

Another one worth checking if the needle roller bearing has been worked on is that
the bearing is free when the clutch centre nut is up tight and the clutch plates are
still out. I've had a bearing recently where both the roller cage and one of the washers
were oversize.

The HT uses BSA fork yokes.

Later pre-unit Gold Stars used a simple fork spring cover which fitted up under the bottom yoke
and seems to have been retained simply by the action of the fork spring. These BSA covers
might be made to fit as the springs and oil seal holders on the BSA forks are (more ...