Yes, the original Booklet L (Tegel Manor) was 8-1/2" x 7" in size.
As far as I know all the small booklets published by Judges Guild are the same size and I have gone through a lot of them.
I do not have a copy of thee book, but I do believe that the Original Guide to the City State book is 8-1/2" x 11" just like the later books for the City State.
As for Booklet "I": the following is just a guess:
Booklet "I" (Eye) was used as a shortcut to the word Initial and that Booklet was part of the Initial Package produced by Judges Guild for its members and sent out in Mailing Envelopes.
The Initial Package was the first product that was produced for the general public in the Judges Guild Line.
The package was first mailed out to subscribers after the 1976 GENCON.
http://www.acaeum.com/jg/InitialPackage.html
During that convention Bill Owen sold some of the Product for the City State (City State Maps it seems) out of the trunk of his Mustang.
1st Printing, Version A (1976): Bill Owen sold this print run of rolled-up maps at GenCon IX (Aug 20-22, 1976) from the trunk of his Mustang.
http://www.acaeum.com/jg/Item0001.html