Nice work John B.

Looking at the World Models Skyraider 1 with cowl cheeks, only (apparent)way to mount the battery in front of the firewall would be to zip-tie it to the outside of one of the cowl cheeks.

How about an APCprop? A Zinger 11x7 weighs .7 oz. while an APCweighs 1.5 oz. How about a hub rather than a spinner. Higley hubs weigh either 1 or 2.5 oz. Adding a backing nut (not needed on a 2-stroke) adds another .5 oz.

Bolt on some lead to the FW.

Since this is a trainer you are probably setting the CGat the "nose heavy"recommended location. As your skills improve you may want to move the weight back. Moving a permanently mounted battery "up front"isn't easy to do. Changing props to a wood prop - no brainer. Swapping a heavy hub back to a spinner - no brainer. Unbolt lead from the FW - no brainer.

Btw, the OS46 LAweighs in at 12 oz. while the OS46 AX (or FX) weighs in at 17 oz and the 55 AXat 18.5 oz. Pretty expensive way of adding weight if you don't want the power. If the power of the LAlimits your flying ability, that's different.

Arule of thumb - to counter balance an ounce of weight at the tail (of most 40/60 size planes) requires 4 oz at the firewall.