Hi Chad,
Just had a look at your photos,
here's the link for anyone else
Very nice!!!!

Don't know anything about the wheels and the brand, sorry. ET23 offset? Should be ok I assume. The idea of 225/60/15's sounds appealing.
Your dissolved fuel line has me thinking I better check mine out. That's scary.
Your Becker Mexico could very well be original. Most had chrome bezels and the pinstripe facade but later models (not sure which year they started) ended up with a more modern looking all black facade that was put in some w123's and early 126's as well. Either way, it's not out of era for a w116 to have an all black becker mexico.
The side repeater is interesting. I remember seeing a 220 cabriolet that was formerly owned by Madonna that had similar repeaters and I wouldn't be surprised if they were attached to satisfy a state law originally. But I've never seen them on a w116 let alone towards the rear. It looks very similar to the ones pictured below.
Good to see your fuel line's back in order. What did you use? rubber or steel/aluminium?
Re: missing strips off your grille. I got replacements from AutohausAZ. You probably know where to get parts but just in case you haven't looked yet, at this particular site, if you go to:
Makes > 1977 Mercedes > 450SEL > Body, Trim & Lighting > Clips and Miscellaneous Trim Pieces , you buy vertical and horizontal clips for the mouldings, then go to:
Makes > 1977 Mercedes > 450SEL > Body, Trim & Lighting > Weatherstripping/Moulding to buy horizontal and vertical mouldings. Not a priority I know but they're so cheap, might as well replace the whole lot whilst your at it.
The biggest problem with sourcing parts for a 350 I've found is that no US sites list 350 parts as such. So many things and I mean a huge majority of parts are the same as 450 parts unless they're specifically for a M116 engine as opposed to an M117.
Good luck on Monday, fingers crossed


