Maybe Preposterous or maybe not RonCombo, you have found a few good prices to go on. I have been able to find modest prices today among some of the odds on. Of your selections I quite like cooper, with jockey and trainer in good form. lots to go against cooper with two trainers sending in two mounts, so an interesting little race. could make a case for quite a few, Pyjama Party looks set at odds on, so cooper a good choice.
Elsewhere I found these to take chance with:
1550 Worc Highland Duke
2005 Rip Showstoppa
1925 Win Lady Kyllar
Best of luck with your selections.