Slightly conical seat (lighter ring):

0.070" orifice on the left, 0.096" on the right. Both for steel-tipped inners, no apparent conical seat:

Some suppliers show a red tip and a different sprung pin, this listed as WZX1100 from Rimmers:

Many suppliers show current-stock HIF valves with a filter, this from Rimmers:

However that has to be considered a 'last-ditch' effort as being so small it would soon clog up and I would far rather swap the much bigger in-line filter fitted before the carbs than replace that valve filter!

Wear ridge (arrowed) in the steel tip led to slight seepage, but only when the ignition was on with the engine stopped for several minutes:

Rubber debris caused running problems, this with some very expensive imported Gates Barricade hose in an effort to protect against ethanol: (Peter Ugle)

More running problems for Peter just 300 miles later, having replaced the hose after the previous episode:

After this the Gates Barricade was be replaced with more conventional hose!