I replied to your post in the other thread, but here goes again in case you don't see that:
Some pictures would help. The washer helps keep the spring from digging into the rubber on the filter. The washer usually sticks to the filter and gets discarded along with the filter during an oil change. They are cheap and still available from Honda. As for the "collar", the only collar I am aware of is the collar that serves as a spacer where the oil filter bolt passes through the "oil cooler" chunk of aluminum heat sink between the oil filter and the lower crankcase. These auxillary heat sink oil coolers are often removed, especially since they require an additional o-ring, and since every other CB750 works fine without them. They can be removed and a shorter oil filter bolt is used. If you have this oil cooler in place, but do not have the spacer collar, then the spring may not be tensioned properly against the oil filter which could allow unfiltered oil to bypass the filter. Is the oil cooler still in place? If not, then you won't need the collar.