Does anyone know if there any manufacturers that still make SL 18 or similar style lamps? Any info is appreciated. Thanks!

I very highly doubt.
Because from normal customer (I mean really normal user, not the old lighting freaks such as us here) point of view they are bulky and rather inefficient (magnetic ballast just has way high losses), so would need to be really cheap to be still attractive. Similar spec (lifetime, efficacy) electronic ones are sold for less than 1/5 of the price these were sold at in their time, plus very likely even these would be more efficient and definitelly smaller and lighter.
And from manufacturer perspective they are expensive (materials for the ballast, the simpl electronic is cheaper today) and the required tube quality to get the competitive lifetime isn't cheap either (complex electrodes forming, tight tolerances on everything...) to make and distribute (heavy, big). So they would need to sell for high price to make profit (like tgeir original prices adjusted for inflation).

So with these constraints I see no way for this to be profitable business anywhere on the world.


But if the point of the question is not that much exactly the magnetically ballasted SL18 but rather the outer shape (big diffusing outer bulb), I think similar CFLs and LEDs are made, but mostly ball shaped.

I was asking about if manufacturers are still making lamps in such shapes. Thanks for the info!

There will be LED lamps made in those shapes I would think. They are made in all shapes and sizes!

I've never seen SL like LED lamps. The closest ones I've seen, are the HID cube retrofit ones which usually intended to retrofit MH lamps inside highbays and lowbays like this: