Just finished this kit using an OS91FS Pumped engine and returned from the flying field with a massive grin all over my face this evening.
All I can say is wow....what a great flying machine.
The engine is perfectly suited...I was using 10% nitro and a 14x8 APC prop.
No problem on a grass strip with the undercarriage as standard. The only change from the standard kit was the use of a fibreglass cowl.
Weight balance exactly as per the plans by putting a servo for the rudder at the back and the battery in the rear fuze accessible via a hatch.

....now I wonder what that 1/4 scale ARTF would be like with my Saito 180....