So I found an interesting score, a replacement motherboard for my beloved IIsi. My current motherboard is a recent one (Late 1992 date codes on the chips) but the SCSI/SCC controller chip has a LOT of green oxidation and corrosion on the pins. Anywayyy, so I bought a board of this guy and lo and behold it was BRAND NEW!!! I guess he had some new old stock from Apple. Like the board was literally untouched by human hands, still sealed in the apple part # bag and everything. Date codes are January, 1993. I now have a brand new IIsi. Maybe I'll use the older, still functioning board to try the 25 Mhz "IIci mod" on it.