The waffenamt is wrong for BSW, WaA204 is generally Rhineland area firms, or near the Rhine like Kaiserslautern & Karlsruhe. BSW Suhl is only known to use WaA4 (WaA6 early)
The ordnance code for BSW Suhl was 936 not 986, - BSW MC's are rare, only seen a couple and both were 936 e/4. While dating these 936 MC's is impossible, we can make some broad assumptions, with barrels supplied to the ordnance system, 936 was used 1940-1941 and dfb afterward but starting in 1941, so such 936 MC's were probably made in small numbers 1939-1941 though none are dated so far as I have seen. ML owned one of these lids, the other ebay 15 years ago.
While I would have no suspicion of BSW making MC's with 936, BSW or dfb the waffenamt would have to be waffenamt e/4 and be consistent with BSW pattens, this does not seem to possess either.
BSW parts and items are well known to have been tampered with, scoundrels know BSW is popular and rare, a good combination for profit, this mismatched MC should be viewed with some suspicion imo.