The rifle in question was taken in battle right off the battlefield. I would say that nickle or chrome plating would make a lot of sense when used in a tropical environment that the Japanese found themsleves fighting in.
The real question is how many were made. It may have been something that was tried and then abandoned due to cost or the extra time to produce.
This gun has the crest intact and it was not ground. All numbers match. It also has a bayonet but I have not yet been able to see if its serial number matches the gun yet.
The gun has the original sling, dust cover and cleaning rod.
Again since we have documented pictures that some type 30 rifles that were chromed then the existence of type 99 rifles that were nickled or chromed is not to be dismissed out of hand.
We also know that nations copy each other when it comes to weapons and their use. I have seen many of the worlds militaries using chromed weapons both in the past and in the present. To say the Japanese would not have done so would to be ignore history both past and present.
At the tail end of the war all weapons would have been scarce and there may indeed have been parade rifles pressed into service. Since this rifle turned up on the battlefield this was obviously the case unless the Japanse were fielding some guns that had been made up for tropical use but produced only in very small numbers.
Ground before plating. To me that kills all speculation over the originality of these rifles.Rice, the ground mum occurred before plating, hence, the reason for my concern. I sold off all my trainers probably 20 years ago except for a serial number 1, so it's not handy to photo and post.