HI Fancy Pants....love the name
I have a 63 GT and have to do the same (if it would ever stop raining)
This 63 has in it's seams - the original vulkum - that is almost in some sections to a powder substance. someones lovely attempt with some black tar stuff in a few other seams - and of course the aluminum parbon - muchly over top of all the other stuff - which most knows that it will not have a good seal to crap.
A big deterant is people don't want to take the time to get the other stuff off and out first - try to get right down to pliable vulkem if any left. Use a picking tool (a recent one I just bought is the gasget and o-ring remover tool from the automotive trade) works perfect.
Recently I have used parbon and more recently I thought I would try the alcoa gutter seal - simply because it said in the description wicks into cracks.
Unless you use a fine nosle on the parbon tube you just don't get it in the crack of the seams - so most ends up out side along the seam line. You can tape it off like some do but you still have a raised bead along the seam. I don't like that look at all.
So I tried the gutter seal in a few places like on the inside on the olympic rivets we just installed the marke lights with. And around the edges of the marker lights because there is an ever so slight cup from the shell to the base. Applied a good bead, waited about 3 minutes or so and then wiped along the edge with a rage sprayed with wd40 - it takes ONLY the excess that is on the outer portion of the edge or (soon to be seams).
I am amazed at how this stuff really wicks into the space that harbors the "rain".
But the key to any job well done - is the Preparation!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
So if you do not want to have your seams leak - take the time to get the crap out of them first. - If you ever have your skins off check all the seams inside too. Ours are okay except the window frame seams - have pretty much dried out. so I will need to do those inside and out.
With the amount of rain we have had I feel like I live in BC - how do you get anything done with all the rain. I know a nice big Garage
I only wish.
Oh yes to get to your question - stick to the main ribs - but you can reach most of the trailer by ladder - if you have the no slip ladders and lay up to the seams. I use a foam floor puzzle type thing that I rest between the ladder and the shell works great.
If you are lucky like us right now - you can just pop up through either the skylight or if you are thin enough - I am 170 too and I can make it up through the vent fan believe it or not
You can reach a lot of seams from up there.
Don't forget your awning rail - always a big source of leaking.
happy sealing - I will be thinking of you when I am doing mine (like I said as soon as it stops raining)