Unusual DEC module: what is this thing?

Does anyone recognise the following DEC module? HIGH SPEED MOS MEM MAT MS1440 G401C This is THE most unusual DEC board I've ever seen personally, and also the most beautiful. This board has an extreamly early example of an LED in the upper right hand corner where a machined metal stiffener is used in place of the usual cast part used on other Unibus boards. This stiffener appears to have been milled out of an extrusion, by hand. Nylon hardware is used along with the more conventional eye-ring rivits. The outside edge of this milled part is stamped 'G401'. This LED is made from a gold-clad machined metal case unlike anyI've ever seen (including those seen on the LED museum web site). I can't see the part number on the case, but I'd bet its a Hewlett Packard. This LED alone may well be worth more than the whole module! The IC's are an orderly mix of grey plastic, gold leaded Intel P1103-1's, and gold on white ceramic (with grey lead-frame traces) Intel 3207-1's. Arrays of individual resistors form high speed DC terminators for the arrays of 1103's and 3207's, and a small handful of TTL parts complete the list of chips. The TTL datecodes suggest its from 1970. The memory chips are not so easy to understand, the P1103-1's are marked: P1103-1 0531 And the 3207's are marked: 3207-1 S183 B0536 Both feature a large 'i" logo to the left of the markings. Clearly very early Intel parts. I suspect that this ~may~ have been a 'live spare' for a PDP 11T55 I once owned and ran many years ago. If anyone knows what this board is, I'd love to know. I can try to get a digital photo made, but that may take some time. If someone 'just has to' own this board, I'm willing to talk. The overall condition of the board is excellent and very few of the decoupling caps have scratches from installation and removal. The unusual edge-stiffener also shows unusually little ware.