I ran your serial #, assuming the last 3 digits XXX to be 999, and below is what i got...

Inland Barrel Type 2A Unmarked 1 - 8069660 Marked "INLAND DIVISION" and dated.
Inland Barrel Type 2B Unmarked 1 - 8069660 Marked "INLAND DIVISION" and dated. Barrels manufactured by BLC Division of GMC will be marked BI to rear of gas cylinder.
Inland Barrel Band Type 3 AI, H.I., JI, KI, SI 6300000 - 8069660
Inland Barrel Band Spring N/A Unmarked 1 - 8069660
Inland Bolt Type 3 OI, AI, SI 5000000 - 8069660 Round bolt.
Inland Buttplate N/A Unmarked 1 - 8069660
Inland Buttplate Screw N/A Unmarked 1 - 8069660
Inland Ejector & Spring Type 3 Unmarked 3150000 - 8069660
Inland Extractor Type 3 W-I, W.I. 260000 - 8069660
Inland Extractor Spring & Plunger Type 3 Unmarked 260000 - 8069660
Inland Firing Pin Type 3 II, NI, RI, R.I., SI 4900000 - 8069660 May also be marked FF.
Inland Front Sight Type 1 Unmarked, N, R, SI 1 - 8069660
Inland Front Sight Key N/A I-I, LI, P.I., SI 1 - 8069660
Inland Front Sight Pin N/A I-I, LI, P.I., SI 1 - 8069660
Inland Gas Piston N/A I-I, LI, P.I., SI 1 - 8069660
Inland Gas Piston Nut Type 2 Unmarked 800000 - 8069660
Inland Hammer Type 4 I-I 6900000 - 8069660
Inland Hammer Pin N/A Unmarked 1 - 8069660
Inland Hammer Plunger N/A Unmarked 1 - 8069660
Inland Hammer Spring Type 2 Unmarked 950000 - 8069660
Inland Handguard Type 3 HI, OI 5500000 - 8069660
Inland M.C. / Safety Spring & Plunger Type 2 Unmarked 5400000 - 8069660
Inland Magazine Catch Type 3 EI, HI, SI, WI 4880000 - 7099999
Inland Operating Slide Type 6 Underlined PI w/Part # 6850000 - 8069660
Inland Operating Slide Spring N/A Unmarked 1 - 8069660
Inland Operating Slide Stop Type 2 Unmarked 1 - 8069660
Inland Operating Slide Stop Type 3 Unmarked 1 - 8069660
Inland Operating Slide Stop Spring N/A Unmarked 1 - 8069660
Inland Rear Sight Type 3 JAO, I.R.Co. 6220000 - 8069660
Inland Receiver N/A N/A 1 - 8069660
Inland Recoil Plate Type 3 BI, DI, PI, WI 530000 - 8069660
Inland Recoil Plate Escutcheon Nut N/A Unmarked 1 - 8069660 Early production.
Inland Recoil Plate Escutcheon Nut Type 2 Unmarked 1 - 8069660 Late production.
Inland Recoil Plate Screw N/A Unmarked 1 - 8069660
Inland Safety Type 3 Unmarked 3000000 - 7099999
Inland Sear Type 3 HI, RI 6850000 - 8069660
Inland Sear Spring Type 2 Unmarked 90000 - 8069660
Inland Stock Type 4 HI, OI 6900000 - 7199999
Inland Trigger Type 2 FI, RI a, RHI, RI 120000 - 8069660
Inland Trigger Housing Pin Type 2 Unmarked 260000 - 8069660
Inland Trigger Spring Type 2 Unmarked 1 - 8069660