To remove John's stitches so that it won't be misplaced with the RDR1 scars position,
and to make it a bit more accurate to how the scars were healed, do this:

Look in your mods and see if you have any mod that replaces cs_johnmarston.ymt.
Mods like Classic Cowboy modifies cs_johnmarston.ymt. if you don't have any mod that replaces it, simply
search for the file on OpenIV and export it as an xml to the stream folder.
The file will be saved as a .xml file.
Open the file with notepad, then search for "0x56B7563F", this is what will come up:

        <Item>
          <drawable>0x56B7563F</drawable>
          <albedo>0x412DC71D</albedo>
          <normal>0x9B83AC8F</normal>
          <material>0x1831393F</material>
          <palette/>
          <tint0 value="255"/>
          <tint1 value="255"/>
          <tint2 value="255"/>
          <probability value="255"/>
        </Item>

Delete this whole entry for every result.

If you have the whole file unhashed (which is unikely if you have an already modded ymt), you should
search for: "cs_johnmarston_ms1_sutures_003" instead.

Do the same proccess, deleting the entry.

Now save the .xml file as cs_johnmarston.ymt on the stream folder. OpenIV won't be able to open
this file and will say that it is corrupted, but it isn't, the game should load it fine.

So that your NPC John won't spawn invisible after these changes to the vanilla edited file,
 replace <UNK_TYPE_0x04BD672F> with <UNK_MEMBER_0x04BD672F> and

 </UNK_TYPE_0x04BD672F> with </UNK_MEMBER_0x04BD672F>

It is unlikely that you need to change this in a modded ymt.