Mec,
I was in a hurry the other day and posted quickly. Checked my Swedish Mauser Rifle by Kehaya and Poyer for a few more details. "The Swedish Mauser" Steve Kehaya and Joe Poyer 2nd ed. North Cape Publications 2003.
Rechecking this manual, I found some pertinent information that may be helpful.
Barrels should have the swedish crown marked on the bottom of the breech and remarked each time that the barrel was inspected. According to Kehaya, model 96 barrels were cut down about 6 inches for the 96/38. There are dimensional difference in the barrel steps between the later Husqvarna 38 model barrel and the cutdown model 96 barrels.
The 96/38 will have a cutdown model 96 stock--you can tell by looking inside the barrel channel where the one and 1/2 lightening cuts are filled at the end for strength and to attach the bayonet stud. You will also see them with the Carl Gustafs receivers dating about when you have them. According to Kehaya and Poyer, the 96/38 numbered about 30,000 conversions to the 24.5 inch barrel--you should also see either remnants of a decal with conversion tables for the new 139 grain bullet or four holes where a metal plate with the conversion information for the new round was removed. Factory mounting had them upside down. Some will have threaded barrels for a muzzle blank firing device.
You do have the correct 96/38 sights for the older 156 grain bullet (m/94 cartridge) with the refined sight adapter. Type 2 sights go from 250-600 m in 50m increments which I do not see here.
Re Stock Disc: You may have the Type 2 first variation stock disk which only designates throat erosion only. The type 2 2nd variation has both throat erosion and bore condition.
FYI Sarco and others had Swede military replacement barrels and unnumbered bolts until just recently that were like new. You also see surplus new old stock military replacement barrels from time to time for either the carbine or the model 38.
My best guess is that someone rebarrelled it with a model 38 barrel (model 96 barrels that were cut down will still have the serial number or the old xxx'd out marks. The new old stock military barrels that I have seen do not have serial numbers and likewise for new replacement bolts. It is possible that someone got sloppy and did not mark the serial number on the barrel as Kehaya and Poyer state.
For further information, there is a guy posting as Dutchman on both Gunboards and has his own website with copious notes and pictures of Swedish Mausers
http://dutchman.rebooty.com
Hope this helps.