The "SQL Server 2012 sp 1 CLR and SMO" runtimes released by "rev23dev" are available for download on InstallAware FTP server.http://www.installaware.com/ia_sql2012_sp1.7z
To use the above runtimes, the contents of the compressed file must be manually copied in the RUNTIMES folder of InstallAware installation directory.
That generally should be:
C:\Program Files (x86)\InstallAware\<IA VERSION>\runtimes
Once again, many thanks to "rev23dev" for sharing his work.