Very nice looking pistol. I can appreciate the feeling of success you must have felt after mating those two components. I'm sure they'll shoot as well as they look together. I have some other help pages on my website that may come in handy in the future, you can look at them here Gun Talk Online
As for separating that tight receiver, try using a dead-blow hammer and leave the bolt in the receiver for some extra surface area. Just be sure that the hammer is in the fully rearward position and the magazine well is empty when separating the two halves.
Good luck and enjoy your new pistols.