As some people seem interested in 4 MB 30 pin SIMMs, I've dug them out of storage; I've got
8x 4MB w/ Hitachi HM514100AS6 (60ns)
4x 4MB w/ Siemens HYB514100-7 (70ns)
each 9 bits wide, so EC/ECC capable on appropriate controllers
Available in sets of 4. They've all been taken out of working workstations and servers years ago and were properly stored. They should work, but I can't guarantee as I have nothing to test in.
Cost: 5 EUR/set + postage from Germany, via Paypal