Can I find out how much a placed image is enlarged/reduced in Illustrator?

Question

I often draw maps using scanned USGS maps as a background image, sort of a hybrid vector/raster map with trails and labels added in Illustrator and the TIFF staying part of the finished map showing contours, texture, etc..
When I start a map I enlarge the scanned map to fit the book format, then I trace the parts I want to replace. The scale of the scans vary, but for the final product I need them displayed at 100% of actual size, at a standard resolution such as 300 dpi.
The way I'm used to working in FreeHand is I position the scan to where I want it and the size that works best for the book format. Then I can use the object inspector to verify what the enlargement of the scan is displayed at  (say x=70%, y=70%). I write that down, then open the TIFF in Photoshop and adjust the scan by that percentage (multiply pixel dimensions by 70% and set dpi to 300) and make my other edits. Then when I go back to FreeHand map, the scan relinks; if I change the display percentage in the inspector and I haven't cropped the scan closer, then it snaps into position at 100% and 300 dpi, and the map is ready to make into an EPS for the graphic designer to drop into the book.
In Illustrator I've found no dialogue box that can tell me the current enlargement or reduction of the scan vs. its original size. Is there such a feature and I just haven't found it?
In the Control bar when I select the scan there is an item that tells me the ppi (display resolution) of the scan. Hmm.  I guess I could use that and compare it versus the native PPI in Photoshop, and type in the desired number, somewhere, to get the scan resolution at 100% for the Illustrator finished map. It's probably MORE direct once I figure out which figure to type where (in Image/Adjust/Image SIze).  Maybe I don't even need to know the RATIO, just the PPI I have and the PPI I want.
But to the extent it's useful to know "the scan is 70% smaller than it should be" it's a big piece of missing information - and I wish there were a way to find this out at a glance.
Ideas?
An aside: One workaround I've found in Illustrator CS4 is to make an artboard that crops to the display area of the scan, then turn off all but the scan and export the resulting file as a TIFF at 300 dpi. Then bring in that scan and place it aligned to the artboard - it sits right where I want it. THAT part is cool. But I am not 100% comfortable exporting a book's worth of background art that all the TIFFs will come out perfect from Illustrator - I feel a little more comfortable letting Photoshop do the resizing.

Answer 1

Thanks, Wade. It's not perfect but it starts to do what I want.
So my first impression is, Oh joy - I'm supposed to use a dialogue box that is three layers down in the pull-down menu, will only work if I pre-select the object, doesn't let me preview the change, and disappears as soon as I make a single adjustment (it can take a lot of nudging to get a scan positioned just right. Click, click, click, click, click).  Got anything better?
Then I went to see where you "turn the effect on or off." (Your saying it's so gave me a little more perseverance). It is NOT done in the Effects list. Clicking there brings up a warning that I'm about to apply the effect again (though unlike some "apply again" commands, the scale values reset to 100%). The warning also says I can double-click on the effect name to adjust the settings of the first time I applied that effect.
Now where would I do that? Reading again, it's in the Appearances dialogue box (i.e. somewhere else). Indirect and klutzy as it first seems, it kinda works. Selecting the scan, opening the appearances box, there's a list of ALL the effects applied to the object. Clicking on the particular effect  (transform) brings up the same transform dialogue box WITH the settings I had changed (scale, angle, etc). Now I can change the values, click OK (the transform box disappears again, drat) and see my changes. Click again on the effects list in Appearances, and the transform box comes right back up, so it's fairly easy to apply, rinse, repeat until things are where I want them.
So as a series of adjustments, the Transform Effect does provide a record of what the current scale settings are, and I think I can make that work. I'll try it out on my partner and see if she says "hooray" or "are you kidding?"
Why this feature is not obvious, is controlled somewhere entirely different than where it's applied, and why the regular transform dialogue box doesn't work this way, is another matter.