Hi Vortech and Garyf,
Thank you Vortech for the tip on accessing the DFS summary sheet from the 3rd print option on the Vic (and NSW) Tab sites. I have been doing that for a while, just saving the PDF files for later analysis. Here some results.
First, I just can't get any meaningful (ie profitable) correlations around either the DFS Ratings or the Skyform ratings. I have just given up on these sets of data. I admire anyone who makes money from them.
I was almost at the stage of thinking there may be no value (for me with limited analytical ability) in the DFS sheets. In a desperate last attempt, I tried playing with the Place % and Beaten Margin figures. This was surprisingly interesting. (I restricted my attention to ratings races, 1250m-1550m, 12 or more starters, Track no worse than Dead.)

I had always looked at Place% in in order from the top down, believing the top % should be the best value (other things equal), then the 2nd, and so on down the list. This not what I found. The results show winners grouped around a Place % of about 40%. Winners almost always come from exactly 40%, or the first three percentages about 40, or the first four percentages below 40. So for a race like today's Race 6 at Coffs Harbour, the list looks like:
TAB No/P%
14 24
10 29
15 31
5 34
9 35
2 38
8 40
6 40
7 43
4 43
12 43
3 44
1 48
11 50
I predict the winner is likely to come from the % range 43 down to 31.

Beaten Margin - the second column on the DFS sheet, is a better indicator than I expected. The narrower the better (watch for last start winners where it is a winning margin, of course). Most winners have not been beaten more than 3.0L last start, although I include 3.5L if the horse is no worse than 3rd in closeness-to-the-winner last start. An odd exception is for horses with the worst Beaten Margin! Even if beaten 24L, back these if they are well in the market- under SP $6, say.
For Race 6 at Coffs, the Beaten Margins in order are:
TAB No/P% Beat Margin
3 44 0.5
14 24 1.5
10 29 1.8
5 34 1.8
9 35 2
8 40 2
11 50 2.3
7 43 3.3
4 43 3.5
12 43 7
15 31 8
6 40 8.5
2 38 12
1 48 35
On these figures I would not look past 3,14,10,5,9,8,11, unless No 1 (beaten 35L) is in the market.

Matching the Place% and Beaten Margin rules for Race 6 at Coffs throws up numbers 5 and 9 (and possibly 1 if backed).
Hope that all is of some interest, guys. Thank you both for pointing me in the direction of the DFS pdf sheets.
Jackact