Type 38 numbers are not related to the serial number on the side of the receiver. If you remove the action from the stock, you will find a letter with a 1 to 3-digit assembly number on the bottom of the receiver. That number is also found on the following parts:

Upper wrist tang
Lower wrist tang
Magazine box
Trigger
Stock (inside)
Handguard (inside)
Dust cover
Floorplate
Bolt
Safety (knob on back end of the bolt)
Extractor
Striker
Rear sight
Bolt stop catch release
Bayonet lug

Hope that helps!

---------- Post added at 02:42 PM ---------- Previous post was at 02:37 PM ----------

As for a value, I agree with the earlier post reference the need for more pictures. Also, does the rifle have an original or reproduction cleaning rod (original has a tapered catch while the reproductions have a more cylindrical catch)? Arisakas are strange in that a "complete" rifle is often cheaper to purchase than if you tried to buy the parts and build one.