You mean the stuff in the attached image? ( how to insert image into the message? )
The blue line specifies the PCB physical outline. Is in file PCB_2_BoardOutline.GKO. Viewing the file in a gerber view program ( gerbv ) will show the right angle corners. The red is the copper pour the original author added. I did not try to fill that in. Did not seem necessary to me.
About the alignment tool - maybe something easier came to me. Just take 3 rectangular pieces of something with nice straight sides and thick enough to be higher than the stacked PCB's. Make borders for the PCB stack by place the 3 pieces of stuff on 3 sides of a PCB to form a sort of cradle and secure those pieces down somehow ( tape ? ). Then nestle a bottom PCB in the pocket, add adhesive and set the other PCB on top. Clamp as needed. The borders should hold it all in-place until the adhesive sets.
The first card listed ( PC ENGINE / HuCARD printed on it ) has 3 offset contacts. Two are extended closer to the PCB edge while the third is set back a bit from the PCB edge. Probably they are like this so those closer to the edge make contact first when plugging in a card. Looks like the extended contact close to side edge of the PCB is +5V while the extended contact in the middle it the pack is GND. And the function of the contact set back is "L level w/Game Card, H w/o GC". On both cards appears the contact is tied to GND so I guess means w/Game Card.
And comparing overall the 2 card designs the plug contacts on the PC ENGINE / HuCARD model are about 0.01 closer to the PCB edge compared to the plug contacts on the HuCARD model ( rounded corners ) . Not sure if this matters or not.
Some web sites state the real HuCARD is 2.4mm thick while another states is 3.0mm. Not sure which is right.
But thinking more about the alignment tool stuff above - poked around the PCBWay site and gathered the following:
For the 1.2mm PCB - need 2 PCB designs fabricated.
If PCBway will combine the orders into a single shipment charge
HASL with lead finish, 50 of each PCB ( 100 PCB total ) == $117.92, $2.36 per PCB.
HASL with lead finish, 25 of each PCB ( 50 PCB total ) == $83.91, $3.36 per PCB.
If PCBWay will not combine the shipping so must pay 2 shipping costs-
HASL with lead finish, 50 of each PCB ( 100 PCB total ) == $141.84, $2.84 per PCB.
HASL with lead finish, 25 of each PCB ( 50 PCB total ) == $114.84, $4.59 per PCB.
Using the 2.4mm thick PCB option-
HASL with lead finish, 50 PCB, $122.93 order total, $2.45 per PCB, no gluing etc., $0.09 difference
HASL with lead finish, 25 PCB, $100.19 order total, $4.00 per PCB, no gluing etc.
So might consider to just use the 2.4mm option. To make 50 total PCB the cost difference between the 2X 1.2mm solution and the 1X 2.4mm solution is very little. And the 2.4mm solution saves from the gluing headaches etc.
In all cases the HASL lead free finish option is less than $10 more if that is a desired option.
About the contact fingers -
Using the HASL might cause connection problems. In the pictures looks like the finish height on the PCB fingers is somewhat irregular. This could lead to contact problem when inserted. Also the HASL finish not the most durable of the finishes for PCB which will be inserted to connectors. The hard gold finish is good for that application.
Looks like the most cost effective gold options are the immersion gold or immersion gold + Selective Hard gold. These cost out the same. The hard gold on the contact would be the most durable.
To make the 2.4mm PCB with the immersion gold + selective hard gold option -
IG+SHG finish, 50 PCB, $162.49 order total, $3.25 per PCB, no gluing etc., increase of $0.80 for the good stuff
IG+SHG finish, 25 PCB, $133.16 order total, $5.33 per PCB, no gluing etc.
So again going for 50, 2.4mm thick PCB seems to be the right option. Not sure how many are needed.