Re: dado fingers question
Just checked a new assembled frame and end bar to end bar is 17 13/16. Top bar of frame is 19 1/16 and need another 1/16 in length from end of frame rest to other end, so frames can be manoeuvered( rests get gummed up with propolis).
Width is not as imporatant as there is more surplus room.
Supposed to be 18 3/8. 18 3/8 minus 17 13/16 just leaves a bee space of 4.5/16 on either end and that is tight. And you are tighter than that.
I'd likely chuck the ends and cut the sides to be ends. But I may be called picky!
I have made supers and it is tricky and now purchase unassembeled pre cut supers.
If you always do what you always did, you'll always get what you always got!