now a deleted NOS part.... the number here are all that is left, once gone, no more. 

Ostensibly for mini, this aluminium insulator spacer will actually suit any HS4 application. It comes with 2 gaskets as well. (I have other spacer types too).

That mark on the photo is not corrosion or pitting, it is just a bit of sticky gunk... I don't know why its there, possibly part of the manufacture many moons ago.

The thickness of the spacer seems to be no particular measurement  but is approx "a tad over half inch"... or if you must... 13.5mm or 17/32" or about 525 thou, maybe 9/16" with the gaskets... as you can see,  nothing in particular.  

I have 3 left  that are NOS Leyland and that is it (see actual number below).

Note local post is parcel only... and signed-for only.  I will not allow anything less for these.   

To look for items in my shop, it is easiest to look in the yellow box to your lower left of "categories".   Select the category of interest and all items in that category will appear.  It is much easier than keywords.