SAEC WE-308N Cueing

I just obtained a SAEC WE-308N and have a question regarding the operation of the cueing. On my arm the lever will lower and raise the arm In a completely controllable manner and I can stop it at any point ( like the description of balanced cueing in the manuals of the WE-317S and 407/23 ), However, it will not " drop slowly if fully tripped " as described in theses manuals. There is no similar description of the cuing in the manual of the WE-308N only a mention in the brochure that it has an oil hydraulic cueing device for the gentle lowering and raising of the tonearm. Is the operation of the WE-308N similar to the WE-317S and the 407/23 with a dampening assisted lowering if the arm is fully pulled down or is the WE-308N only manually operated in both lowering and raising with no dampening assisted lowering at all ?. If there is supposed to be a dampening assisted lowering my cueing device must have lost the hydraulic oil. If so, is there away to replace the oil ( probably silicone oil ) in the cueing mechanism ?.
I have this arm, bought it in the late 70s in NYC, its now in a box, and as I recall it worked as you described it should, slow arm drop if fully tripped. So it should be dampening assisted lowering. My question to you-why is this an issue for you? Not being flip here, a real question. I have no idea how/if to add oil, etc.
It's not a big deal since it doesn't just drop so I can lower it manually. I just wanted to know if and how I could return it to compete working order.