Paul - Just think , That big 60" is one heavy SOB , and over the years has been beatin' around , up and down , sideways too . To get everything perfect would be a major undertaking , and could involve welding to tighten up holes , new hardware , etc , and possibly some serious deck frame straightning/tweaking .
I know you are looking for some Happy Medium to get you going without a big lot of hassle . I wouldn't f-fool around with the angle lift thing,as yours have not been flipped , which simply means that the L arms can rotate 180 degrees if the lift straps that go back to the rocker shaft , and the deck lift arms are not connected to them. Has nothing to do with moving them to the opposite side of tractor ,or even removing them . But yours are oriented the same as mine are , {still not saying mine aren't flipped wrong} , but I'm pretty sure they're not . Maybe some one else can look at your picture and chime in on the L bracket lift angle arm . Like I said , I've never been happy with the "lift" on mine . It had 1000 hrs' on it when I got it ,with split time between mowing and front blading.
I like the idea of altering the end of the lift strap at the rocker shaft connect point to affectively shorten the strap for more lift, but only if all other adjustments prove ineffective first
You WILL get this thing done.
Dave