You have some things working against you: In 1933, there were precious few cars produced due to the depression. Only 3482 LaSalles were built that year. There are those in the Cadillac & LaSalle Club that own these cars. Unfortunately, only a small percentage of club members read this forum.
The best way to get in touch with other 1933 LaSalle owners is to join the Cadillac & LaSalle Club (follow this link: https://www.cadillaclasalleclub.org/joinrenew
). Once you join, you will receive a copy of the International Membership Directory
. The nice thing about the directory is that it is cross-referenced by car. So you turn to the section for 1933 LaSalle and listed there are the members of the club who own 1933 LaSalles. You can then contact them for assistance.
Another thing you could do is to purchase the Club's book, LaSalle - Cadillac's Companion Car
. Owing to the rarity of the cars, there are only 23 pages devoted to the 1933 model year. But there is some great information there in those 23 pages. Available at: http://store.cadillaclasalleclub.org/product_p/lasalle.htm
Another option is to purchase the Authenticity Manual for 1927 - 1933 LaSalles. Available at: http://store.cadillaclasalleclub.org/product_p/class%203.htm
For low production cars like this, joining the CLC is your best bet.
Hope this is helpful to you.