Thanks Truckcop,
The aft end of fore-end moves to ground and sticks there after firings, about 5-8mm. The barrel is tight. There is a spring with clip in front of fore-end follower assembly with clip, but no washer--nor is one shown in parts list that I can see. Is there a round washer in the fore-end follower assembly not shown in parts drawings? That could be it, if missing. The plastic cylinder at base of the forearm is present. Any spec on the absent washer if there is one?