Shaun
Here are my edits…
I added some points for traciability

Purchase Agreement

All newly constructed Ready-to-Fly or Almost-Ready-to-Fly remotely-controlled model aircraft intended for use with turbine engines shall be assigned a unique airframe serial number; each critical component shall be marked with the unique airframe serial number and shall be shipped with the following required photo documentation:

1. Clear color photos of main wing internal construction prior to installation of the sheeting/skin (showing spars, ribs, hard-points, hinge-blocks, landing gear mounts and/or any other critical structures) with the airframe serial number clearly shown.

2. Clear color photos of tail plane construction prior to installation of the sheeting/skin (showing spars, ribs, shaft bearing blocks, anti-rotation hardware, hinge blocks (in the case of vertical fins or fixed stabilizers with hinged elevators) etc.) with the airframe serial number clearly shown.

3. Clear color photos of any area or apparatus that is considered a critical structure and is not visible to the end user without extraordinary inspection (such as cutting into closed structures) with the airframe serial number clearly shown.

It is understood that this requirement will add a small amount of time to your process, so a nominal surcharge for the photo-documentation package should be established prior to the acceptance of the order by both parties. Please understand, however, that this photo-documentation needs to be of each individual model and not a batch, general sample, etc. The purchaser needs to be furnished with the above-described documentation for the specific, individual model with the unique airframe serial number clearly shown in the photo documentation. Again, this documentation shall be considered a necessary included component to the shipped model as much as a fuselage or wing is.

Note: A purchase agreement shall not be made unless this documentation is supplied with each kit or ARF, failure to supply the documentation package will result in a rejected shipment and a full refund of the purchasers funds.