Seen that more often those mislabeled rom's…. The Jungle Lord home rom is fine; haven't had any issues with those.
Leon's testrom is not very reliable in detecting faulty memories. If desired I can send you testroms in coded myself. Better memorytests and also giving you the opportunity to test socket 14, 20 and 26 with dedicated test rom's (also included). And more options. Send me a PM if you are interested.
Also...there is still a AMI branded 6802/6808 on your CPU board. These are unfortunately well known for causing problems after aging. Doesn't hurt to try another one (borrow from soundboard if socketed).