A Scott Testing Question

A question for the Scott engine aficionados amongst us. Whilst stripping the engine down, in preparation for the restoration process, I was reminded of a feature that I had previously noted on other Scott two stroke engines, in these sets. Being an air cooled engine, using the forced air induction principle, the engine unit is fully encased in a cowling. The three surrounding sections being politely identified as corsets! On one of the sections, which is located around the carb, the exhaust manifold and the base of the engine there is a boss that is braised in, into which there is a threaded plug inserted. These items are identified as "Boss: Test Connection" and "Plug: Test Connection", the test connection simply opens into the void between the cowling (corset) and the engine fins. The question is, what test equipment was connected into the boss and for what purpose. I will open the bidding, by suggesting it was either used for a temperature probe or possibly some form of air flow indicator. Whatever it was actually used for, it seems to be typically over engineered, for something which it  seems would have only been used once, during the commissioning process.

If anyone knows for certain what the use was, or has any other suggestions as to its use, I would be please to hear.

Thanks,

Neil




The Boss and Plug for the test connection, fitted to the engine Corset.




Inside of the Corset, showing the heavy brazing used to fix the boss.




The test boss is positioned in the corset, adjacent to the flywheel fan. (Top cowling is not fitted)