The only differences between the v1.1 revA and revB are this:
The ICSP jack was a 2×3, 0.5″ pitch male pin header on Mayfly v1.1 revA.
The ICSP jack is now uses Tag-Connect pads for use with Pogo pins for ICSP programming for the Mayfly v1.1 revB.
And with the revA boards, there was a circuit design change after manufacturing that required me to hand-solder a small jumper wire to bypass solder jumper SJ26. It is noted on the schematic. That change was incorporated into the production run of the revB boards, so electrically, revA and revB boards are the same, except there’s a physical wire on revA and a board trace on revB. There’s also a dab of conformal coating covering SJ26 on all revA boards to prevent it from being used. This is noted on the Jumper Settings page if you scroll about halfway down.
As for the schematics, they are available for all version numbers via the links on the Hardware page you linked. Click on the name of the desired schematic version, it’ll take you to a preview page. The schematic shown on that page can appear fuzzy or low-res depending on your web browser and monitor size/resolution. But simply click on that image of the schematic and you’ll be taken to the actual pdf file which is a high-res 11×17 pdf that can be printed or zoomed in on, allowing you to see all the details.