Engine well firewall insulation/sealant 69 GT350 build date 1-9-69 In Dearborn

[SChatman]

Question on the firewall sealant/insulation, does the spray on sealant go on after everything is bolted on to the firewall to seal the pass through's and any place that might leak air from the engine well? I saw a Shelby of my year that had overspray on the heater hoses, brake lines, Vacum hoses and pretty much everything on the firewall but this car had been restored and I'm not sure it was accurate.
Thanks in advance.