Hey Jerry! I just read through the entire thread, very interesting stuff going on here! What's the status of the 45 now? I'm curious if and how you were able to rescue the frame. Beautiful engine, garage, and welder, BTW! Your experience makes me wonder how deep I want to go with my newly acquired 40. It runs well and looks better than "good enough for wheeling".
It's sitting in a storage unit awaiting my focus. Ramon has the engine running and installed in his 40, I'm thankful he could put it to good use.
As of today, I have the 6.2l and tranny Johnny pulled from the CCUV truck planned as the power plant, the unlocked 80 axles that are currently on my 80 (awaiting swap of locked axles I have sitting in my garage) will get re-geared and ARB air-lockers underneath, the frame has been saved from rear cab-mounts forward, fabricate new rear section to accommodate 4-link, 3-link front but...the biggest question is all the rust repair and how best to deal with it, in particular, the bed. I've got the cab forward covered with a recent acquisition of a solid hood (thanks RK). I may regret not getting in on the Awlteq thing or other bed options, all over $3.5k options, a number I'm sure I'll surpass in time trying to fix/repair/modify the one I have the tail gate being the most challenging aspect.
All of this fantasy build is waiting on finishing my 80, swapping the freshly rebuilt/re-geared/Longfield/Aisin hub, factory e-lockers, swapping the rebuilt/Marlin gear/viscous coupler removed transfer case (not complete), upgrade upper/lower control arms, finishing my rear swingouts this weekend which will allow me to get focused on the t-case work. What a can of worms I've created for myself...

Regarding your new 40, it all depends on what you want from it. Enjoy it, do some preventative maintanence and get to know it for a while. Identify mechanical issues that may need addressing, look for rust and document so you can make a task list, something I didn't do. If I were in your shoes, I'd keep it stock other than some 33 X 9.50's, consider upgrading axle components (re-gear/aussie/ARB air lockers), upgrade music/GPS/CB/Ham electronics and drive the crap out of it.
In the event you find rust such that it needs immediate addressing, the engine has a significant issue or find safety issues, AND have the extra space, extra time and extra truckload of $$$$, consider doing a frame-off but don't lie to yourself that it will only take a couple weeks/months/years. There are no short cuts, if you want it done fast, it takes loads of cash, if you do it yourself to save cash, it takes loads of time, trust me on this...