Shift linkage fix -6 conversion:, back on the road Options

[Retroracer]

All - so on the way home from WCR2020 I noticed issues with shifting in the 1st/reverse plane, accompanied by what felt like metal / metal contact (grinding). For reference, its an early chassis (1970) previously converted (in a former life) to side shift. I made it home and found the following:

The link rod as it sits in the bulkhead has a 24.8mm dia., and when I did the -6 conversion I replaced the nylon bushing with a new one and assumed all was well....! The recent failure seemed to be the new bushing had deformed/worn, allowing the front linkage to scrape internally when the shift lever was pushed hard over to the left.

I ordered one of the Tangerine Racing spherical bushings, which - on the surface - seemed like the perfect part for the job. When the part arrived, it was clearly designed for a narrower diameter shaft at the bulkhead exit. I extracted the front linkage to examine, and it has been modified with what looks like an outer tube welded over the narrower internal bar - so the bigger diameter is only for 6" or so. So - questions the group brain for best solution:

1) Do I have to de-modify (in other words find a stock) front shift linkage to make it work with the TR spherical bush? Don't think having the outer turned down in a lathe is a great idea...
2) Is there an alternate larger dia bushing that lasts longer than the 6000 miles of the nylon one from a known good source? Then I can keep the front linkage bar as is....
3) should that front linkage actually be straight? Or should there be some kind of kink in it to avoid that internal interference in the central tunnel? (and hence less pressure/wear on the bushing)
4) Should I try and ream out the TR spherical bushing to accept the larger tube? <grimace emoji> Am hesitant to try this as I think the front shaft is the issue not the bushing design.

Any and all wisdom and/or pointers to reference posts welcome

- Tony

Pics of the modified front link for reference: