Congrats on getting a 50 Merc. Yes, catalogs are available both in reprint and used. Look here.
https://www.bing.com/search?q=1949-...YOdIBCDk2NThqMGo0qAIIsAIB&FORM=ANAB01&PC=HCTS
and
https://www.lincolnoldparts.com/parts-books
and
https://www.ebay.com/sch/i.html?_fr...1949-51+mercury+chassis+parts+catalg&_sacat=0