There are four different ways to get your Samsung ML-1710, ML-1740, or ML-1750 printer to work in Lion:
Samsung Driver from Samsung Australia
http://samsung.com/au/support/detail/supportPrdDetail.do?menu=SP01&prd_ia_cd=&pr d_mdl_cd=&prd_mdl_name=ML-1740
Download the link under "Driver" that has the file WebLBP_SPL2.zip (Version 0.97, 04 Dec 2008). The 1710, 1740, and 1750 are compatible with each other, so it will work with all of them.
Note that, with computer equipment, it's very common for manufacturers to abandon support for something in the United States, while the exact same product continues to get support and/or updates in other countries. If you ever again have trouble finding a driver for an older product, look for them on the web sites of the manufacturer's non-U.S. offices.
Also, there are some open source projects which enable printing on older Samsung printers in 10.6/10.7:
Samsung-GDI
http://linuxfoundation.org/collaborate/workgroups/openprinting/macosx/samsung-gd i
GutenPrint
http://gimp-print.sourceforge.net/MacOSX.php
SpliX
http://guigo.us/mac/splix/
You said that GutenPrint was working in Snow Leopard but stopped working when you upgraded to Lion. Did you do the obvious, like re-install it? %-)