How to import blender file into unrecognized package in S4S?

I'm currently working on a conversion set (from S2). The wrought iron stairs, railing, and fence, and I'm going to create a few decorational items to go with them (catwalk stuff). The stairs and railing are done. Now I'm on to the fence and figured that once we have the time to get them into the tool my notation here will help.

STAIRS
The group cannot be 80000000 must be 00000000 also the AuralMaterial1 must retain the base clone value. Otherwise the game will not generate a thumbnail.
MAPPING MATTERS! The way the UV map is designed is interesting to say the least. For my conversion I kept having improper texture stretch on the step. I flipped and rotated and tweaked until I got it right, lol. The way the mesh is cut is also interesting. It is cut into 3 sections (all still one group though) left (solid black vertex), right (255 red vertex), and center (255 green on the left and solid yellow on the right)

In the stairs resource there is a U1, this is the material variant VariantId. Used to determine which variant thumb to display.

RAILINGS
Very similar to counters however the group also cannot be 80000000.
There are 8 "ModelKeys"

1. Top for short
2. Top for Med
3. Top for Tall
4. Top Post
5. Top Fence
6. Bottom Post
7. Short Section
8. Long Section

FENCES
The group also cannot be 80000000.
There are 7 "ModelKeys"

1. 1 tile straight both ends    Example: model instance 0x35A2C363BDDE9860
2. 1 tile diagonal both ends   Example: model instance 0x7681C6F431707D4B
3. 1 tile straight right end     Example: model instance 0xCB28497707FB4A1A     These are only used if there are no posts between sections.
4. 1 tile diagonal left end      Example: model instance 0x03698F852EBC4B78             "
5. 1 tile straight no end        Example: model instance 0x5114D19F6D044FD9             "
6. 1 tile diagonal no end       Example: model instance 0xE767AE0A6FAF0E61              "
7. the base post                   Example: model instance 0x4378B5E7F153AC79

There is "ModelList1-4" There are no shadow meshes just an alternate mesh including the end posts (either on one end or both). I'm assuming for stair placement (it cuts out a part of the fence)

1. ModelList1 = no end posts
2. ModelList2 = right end post
3. ModelList3 = left end post
4. ModelList4 = both end posts

Inside each you find 3 "BuildModelEntry" each with a "U1" value 514, 1028, or 1542. These represent which size that model is for. Smallest # = smallest round mesh, med = med, etc.
So this means that there can be up to 19 models! Each with its own lower lod.