There is a procedure for making indole-3-CHO from indole in http://rhodium.lycaeum.org/chemistry/vilsmeier.txt (http://rhodium.lycaeum.org/chemistry/vilsmeier.txt)
http://rhodium.lycaeum.org (http://rhodium.lycaeum.org)
I see no reason for your synth to not work in theory, but there could be a few modifications:
Nitroalkene => indolylacetone could be done with Fe/acetic acid as in Pihkal #109.
Indolylacetone => AMT could be done with NaBH3CN or NaBH to increase yields.
http://rhodium.lycaeum.org (http://rhodium.lycaeum.org)