Hi!
I am assuming that the second dish is tied into the dpptwin input (normally on a d1000 for 129) or that you are using a switch to combine the satellites. When aiming at 61.5 seperate from another satellite (signle lnb) signal strength is generally 110-120. It is highly easy to locate and very strong...! YIPPIE!
I have heard some of my techs talking about the difficulty of getting good signal on 129, and my only advice to them is to tune out 129 first. Doing this, 110 and 119 are generally strong enough (90+) to hold their own, while getting about 85-90+ on 129. But combining all on one satellite and balancing out the signals seems to be a bit tricky - probably because we are all stuck in superdish mode...LOL
Good Luck!
I guess the advice is, just try it and see what happens. You will not be able to "fool" the satellite system into thinking that you are still pointing at 129 when you are aiming at and getting signal from 61.5. It's an automatic recognition thing that you cannot and would not want to bypass. So, if you are receiving programming from 129 that is unavailable off 61.5, kiss it goodbye until you swing your dish back around the 129 way.