Type 38 Carbine Questions

[Singer B]

You know you are in trouble when you walk into your local gun store and the owner asks you "can you please take a look at something for me and tell me what it is?" He presented the rifle to me and it was obviously Japanese but very short and definitely not a Type 99. After several minutes of on-line research, we were able to identify it as a Type 38 carbine. The person who brought it into the shop was an 80+ year-old gentleman who claimed he received it from his father's closet many years ago and was all-original. We eventually made a deal and I brought it home today.

It is in really great condition (maybe too good?). It has an intact mum but the numbers I have seen so far do not match. It has obviously been apart as evidenced by the boogered up screws. Here are my questions:

1. It has a cleaning rod. Is it original?
2. The wood and finish are really nice. Is this the original finish? I have not seen this type of deep brown coloring on any of my other Japanese rifles.
3. I believe it is a Series 5 Nagoya?
4. Anything else you can tell me?

I will start the conservation work this weekend but wanted to confirm the above information before I moved forward with certain processes.

Thank you for your assistance!