My answers, bear in mine I'm kinda weird (my wife keeps telling me that.....) My reference is my 1970 safari
-If the wheels are original, should I assume they are split and budget accordingly? -------Mine were just ugly, not split rims
-The axles aren't seized, but the arms have 0 down angle. Is this a 'must do' right now? (I am budgeting for axles regardless). When (not if) I go Dexter, how much should I assume? ------- I camped 2 seasons and a lot of miles on a bad axle. Not good, but not necessarily unsafe (warning, can-o-worms alert) I did my replacement for less than $300.
-Is dent removal even possible? There are a couple of zingers. ------- See my "days of destruction" thread and many others.
-It has the double bed, but I wanted twins. Has anyone done a conversion? Seems simple enough. ------- Yep, do you not have a spouse?
-Everything works (but again, I am budgeting for total appliance replacement), is anything dangerous to use in the meantime? I have heard of furnaces being a death sentence. ------- "everything works" - really? I want this trailer! Be careful with 40 year old propane burners. It only took about a month for my eyebrows to grow back. My furnace was way rotten. I shouldn't have even tried to fix it.
-Not having a gray tank will be an adjustment. Anyone know the black capacity? ------- Nope, sorry.
-What should I look for? Anything specific to this model/year? ------- Taillight deterioration. I completely rebuilt mine with LEDs after trying to stay original. Bad idea. LEDs perform much better, are more reliable and brighter.
-I forgot to check, would an original fridge work on electric as well as gas? ------- yes, see warning above re: propane.
-Dumb question time-----The spec sheet says the hitch ball height is 19". I forgot to bring a tape. Does that mean 19" to the inside-top of the coupler? If so, Progress is going to get a piece of my mind on what they charge for hitch shanks. ------- ?
-Floor rot - What would be a rough time estimate and procedure on replacing the subfloor under the front goucho? ------- 10 hours tear-out, 8-16 hours replacement depending on tools and ability, 10 hours put back together. This will vary depending on how many interior skins you need to pull to gain access to the bottom track containing fasteners. Then of couse you will need to repair the rusty rotted out frame sections you didn't know about. Add 1 week.
There is lots of (but not exclusively) plexiglass in the exterior windows. Was any standard? What is a good estimate for time and materials to do window seals? ------- thats on my "to do" list.
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Let me add my "how I would do it again" advice....
1. Make it safe to use. This means safe to tow, and safe to sleep in. Make sure nothing is going to fall off the trailer. This includes bellypan, bumper, storage doors, AC covers, awning. Make sure you hitch is working correctly. Replace the safety chains. REPLACE THE BRAKES. Get the taillights working, Rig temporary ones if you have to.
Safe to sleep means don't light that furnace to use at night unless you know that it won't kill you. Same goes for electric heaters. Don't run a high amp heater on 40 year old wiring without checking it out first.
2. Get it as watertight as you reasonably can. This will suspend the decay.
3. Get it clean. This just makes it nicer to use.
4. After you've camped a few times, figure out what priority the repairs should be. Personally, I would hold off on the floor and dent repairs until I figure out if I really want a gray tank, or to relocate the beds, or other major changes. Things will just flow better once you have time to develop a plan. Plus, it really helps to use stuff first then learn what you want.
Good Luck!