Lookin good!
I would suggest adding some doublers in the front, and adding some extra beef to the wing. A trainer is best built using crash-proof structure, otherwise it quickly becomes a fly n fix bird. This adds some weight, but adds to it's survival during the learning process.
I usally add a 3/32 dowl across the front of the L.E., makes it MUCH able to survive even small tree impacts, and is easy to cover with as the round accepts the covering without added sanding. Very little weight is added, but it will add many more flights.
Don't mean to rebuild this for you as it looks great, just considering who the trainer would be used by and all.

Remby