When I took my Combat breather apart, it did not have the separator in it, I might have not have assembled it with one years ago when parts were not so readily available ? When I rebuilt the engine. So I did put a new foam in.
To prevent wet sumping .
I put in a shut off valve in the oil feed line from the Oil tank to the engine. Also I did install an oil pressure gauge , so I would know if I forgot to turn the valve on. So that is not a worry. And the Combat will no longer wet sump.
AS for the foam.. it could have been pushed into the oil tank ( in small pieces) when the sumped oil was forced through it. But it would be in small pieces over a period of time. Or some of it went into the oil in the base and returned to the oil tank. In very small pieces over a period of time.
For years I have used these as my vent valve. Because the Combat will pump sumped oil through the breather, I think I'll be OK as the shut off valve will not let my bike sump. , I know this type of vent valve works in my other bikes , 1973 -75 models , so I'll be testing the results as weather permits on the Combat.
I was lucky the valves I brought , recently, were NOS and made in the USA and very inexpensive. So I hope the testing goes OK, but I will keep my eye on it. I just installed it on the weekend , so the new "plumbing" is new to me. But so far so good.