Smoke unit replacement

That smoke unit will smoke fine, I would not attempt replacing it with the MTH.  First off, the MTH is larger, and it's mount is different.  You'd also have to change the resistors and the wiring to the smoke unit.  You have to take in mind that the electronics driving the smoke unit also have bearing on the smoke volume.  You're asking for trouble trying to "improve" the smoke here.  I tune Lionel smoke units to smoke just fine.

How do I contract your services?

If you're willing to open it up and can do basic mechanical work, you can do this yourself.

I was referring to another job. A polar express upgrade 😉

OH, that.  You can use my profile email address to contact me.