Christies auction page:

An Apple-1 motherboard: labelled Apple Computer 1 Palo Alto Ca. Copyright 1976 on obverse with four rows A-D, and columns 1-18, white ceramic MOS Technologies 6502 microprocessor, 8K bytes RAM in 16-pin 4K memory chips with an additional 4k piggy-packed onto on RAM bank to create 12K of RAM the heat sink removed along with voltage regulators which have been placed onto the metal casing enclosure (which acts as a heat sink), original 3 “Big-Blue” power supply capacitors, firmware in PROMS (A1, A2), low-profile sockets on all integrated circuits, fitted with original Apple cassette interface card lettered with “G” within triangle, above D9 is an added 1702 EPROM ; the metal casing painted green with Datanetics keyboard to front (20 ¼ x 17 x 6in.) ; vintage Viatron monitor model no. 3001-301 (20 x 11 x 9in.) ; in working condition. Provenance: The EPROM and extra RAM added by the first owner; acquired by Frank VanGilluwe III; sold to Andrew “Zack” Zacharias for $300 May 1978.

The auction is scheduled for next Thursday, June 15th.