I collect home micros, and I recently acquired a Mac 128K. However, it's been quite heavily modified with contemporary third-party add-ons. It's been taken up to 1M RAM and it's had a SCSI interface installed. The memory has been taken up to 512K by removing the 64K x 1 bit RAM chips and replacing them with 256K x 1 bit chips, plus adding a few discrete components (not hard, considering the 128K and 512K Macs shared the same PC board). It has then been taken up to 1M by adding a third-party 512K RAM expansion board, which plugs into one of the RAM sockets (the chip it displaces being installed onto the expansion board), and is connected to the address decoding by several flying leads. The SCSI interface has been installed by removing the ROM chips, plugging a daughterboard into the empty ROM sockets, and plugging the ROM chips into the daughterboard. The SCSI socket replaces the cover over the battery in the back of the Mac.