I've been involved with several of these Cessna projects at this point, currently one for myself, and consulting on a second (both 170Bs.)
As have been advised above, my strongest thought would be to find another bird.
In my experience, the only reason anyone ever gets involved with projects like the one you presented is because somehow one develops the notion that it is a way to get into a Cessna cheap...
The unvarnished reality is that what you are proposing will in the end, cost you multiples more than any flying airframe you find.
Over the past 2 years, I have been fortunate to have traveled the four corners helping folks find the right Cessna TDs, and perhaps twice a week I have the same 60 min phone call where hungry Cessna buyers discuss what they want, their mission, their goals, etc etc etc... Invariably at some point in the call they say something akin to, "they all have damage, it doesn't matter, and if its fixed correctly, it doesn't bother me..." After surveying dozens of Cessnas now, I can assure you that it matters...
The point is, and all things considered, if you have a choice, it's better to start with the least amount of damage possible. (unless your plan is to not disclose the repairs... I have seen more examples of this than I care to recount.)
A "restoration" like you are talking about, if you do it the "correct" way, will not cost you 100k, but well north of $200k in parts, (I would guess the list you discussed it maybe more like $250,) and that's excluding the airframe. Folks can convince themselves otherwise, but eventually they either abandon the project, cut corners so they can finish, or swallow an uncomfortable dose of reality on their way to an emptied bank account.
Even if someone were to give me an insurance bird like you are talking about for free, I would most likely still choose to bide my time and find myself a low-ish time bone stock flying airframe (they are out there.) In the end, come out ahead.
One last item for thought... The reality is that all the "mods" and "restoration" you are talking about doing are the exact same parts and steps that you would do on a 170B or 180. What I mean is aside from the initial acquisition of the airframe, the resto-mod on both cost pretty much the exact same.
Of course there are factors that might change my rubric such as the cold economics of the wallet or an unbridled, subjective love for the 170, but in most cases, the argument for the Skywagon typically wins out... Here is one way to look at it: You drop $250k in parts to build a Cessna bush-bird, and you start with a $100k bone stock C180 vs a $40k bone stock 170B. In the end, the delta is $60k... That's a bunch of dough on its own for sure, but if you look at it from the backside, with the 170B, you are almost $310k into a bird that (today) might only be worth $125k on the best of days. In the case of the 180, you spend $350k, which when finished, could easily be worth $225-$250k... AND, it will fly faster, carry more, go further, and be in general a more betterer platform. And... this is just parts. NO LABOR. FWIW, I have over 6500 man hours in the restoration of my 180, and it's still not finished. LOL.
Big numbers for sure, undoubtedly higher than some of the older, legacy minded enthusiasts are willing to swallow, synthesize, or perhaps appreciate... but from someone who has been doing this every day now, it's hard to get out from under the reality.
All that said, we, as aviation nuts have the right to forgo common sense, throw our balls over our shoulders and charge into the fire... and, unrelated to reality, can sometimes turn the foolish choice into the correct choice. Cessnas have both enriched and changed my life, and I dont regret a single minute of the roller coaster ride... So good luck with whatever you choose!
In the end, Lopes advice is probably the most sound where he says: "I say go for it..."
Feel free to reach out privately if you want to to toss around some ideas. This topic has occupied most of my waking moments over the last decade, and am always glad to share my thoughts... (as you can read, I don't have any strong opinions. LOL)
Best,
Greg-