About this detail of the Tiger
Rye Field have used the same firewall in their Mid Tiger that they used in their Early Tiger. But there were changes made to the Tiger as it went from Early to Mid, and some of them were on the firewall.
The two levers, marked "1" in this photo, were used to engage and disconnect the fan drives of the HL210 engine. They were deleted when the change to the HL230 was made. They are not appropriate for this model and you should cut them off.
The two knobs, marked "2" in this photo, were used to seal the air ducts between the engine and fan compartments. They were deleted when the underwater travel capability was omitted. They are not appropriate for this model and you should cut them off.
There are four slots in the middle of the firewall, indicated in this photo. They are air vents for a HL210 engine. But "mid" Tigers had a different kind of engine and did not require these slots. Instead, they had a hinged door.
Here is the middle of the firewall in a Late Tiger. The small open door is what replaced the four slots.