My worry is that all the lines required to dump blobbed ROMs aren't bonded out. The ROM data comes out S1-S8, but after a quick look at Contra, I only see 5-6 traces for those signals coming out from under the blob. I'm guessing the other 2-3 aren't bonded, which means you'd have to remove the blob and use probes on the die pads to access that data.

Other LCD games might bond out all the signals and even have test pads to verify the ROM data, but I bet that by this time, yields and confidence were up, and full ROM verification was no longer done.