Restoring vintage sets with modern elements?

[NathanR]

I recently got hold of some of the earliest Lego Technic sets, including the 852 Helicopter and 855 Mobile Crane. While they were sold as "complete", it's obvious to me that the previous owner restored them using modern Lego elements. For example, the 852 has technic pins that are light bluish grey, and a 1x4 technic brick with hollow anti-studs. The 855 has a yellow 4x6 plate that misses the bars across the anti-studs and is visibly more translucent, and also some inverted slopes where the hollow studs are thin-walled. Interestingly, some of the 1x2 tiles only had numbers 1-12 stamped into the underside, except for some modern replacements that have  "Lego 3069" in italics.

Now, I realise I'm obsessing over details that probably don't matter. Lego elements from 50 years ago are compatible with those of today, and these sets are so old that it would be incredible if parts hadn't gone missing and been replaced. But I find myself wondering - should I leave the sets as they are, respecting their history? Should I do a partial replacement to ensure all elements are at least the correct colour (like, light grey pins instead of light bluish grey)? Should I start searching bulk Lego bricks for elements that match the correct mold variations for the era (and probably drive myself crazy in the process)?

What would you do?

[Jundis]

As I don't own such old Lego I could only give you advice for what I think most collectors would do:

Buy the original parts from bricklink. There are plenty available and also cheap (pins normally cost 1 cent each). Just check the part list for the right item number and the right colour.

https://www.bricklink.com/catalogItemInv.asp?S=852-1

https://www.bricklink.com/catalogItemInv.asp?S=855-1

You just have to watch out when ordering the older parts. Maybe check back with the seller if they just write "used" in the description. If there are sold with "good quality" or "excellent" there should be no problem.