Old Toilet New Install - Help Needed

Good Day! I am seeking a little help on what I can do to install an antique 1880s toilet in my home. This toilet came out of a mansion in Oregon and it was never used. It is a pull chain that has an oak wall mount tank with copper lining (gorgeous) and the porcelain commode is ornate blue and white floral leaves with oak seat and lid (exquisite). I am going to try to upload photos. It is called "The Reform". I cannot locate another one like it.
Call me crazy, but I am remodeling my bathroom and installing an antique clawfoot tub and I absolutely need this toilet with it. I love antiques.
My problem- This toilet has a rear waste line and it angles down at 22ish degrees (I believe). It is a 4" line, which I want to work down to a 3" to install it in the existing toilet plumbing in my home. The end is Not threaded - it is just lines and it has what looks like glue or grout residue on it. I need to know what I can do and parts needed to install this work of art and have it functioning properly without a lot of issues. I have no clue about parts I will need (only for the plumbing- I am good on the toilet parts), and I am hoping that I will not have to connect several pieces of elbows and conduit that will make the plumbing look unsightly or stick out from the floor or wall ten feet. I hope that makes sense.
I also had a thought about changing the angle and running an elbow up so it is straight and hooking it up through the wall into the existing waste piping. Any thoughts? Can this be done?

 

FWIW, the building inspector may not be as thrilled with that toilet. Also note that some of the older ones don't really work all that well.

It's generally a really bad idea to neck down any drainage piping, so going from a 4" outlet to a 3" one would not make an inspector (and maybe you during use) very accommodating or happy. There are places for antiques. Not sure this is one.

Good luck. You might be able to use something like a Fernco donut, but it won't look all that great. It would depend on the actual ID and OD of the opening. In case you ever had to pull the toilet, you'd want it to be able to come apart easily without a major effort.

FWIW, don't think the tub will pass an inspection, either. If the drain got clogged, having the tub spout below the rim is not allowed as it can pollute the water supply system affecting not only you, but people on the same supply line. There must be an air gap between the top of the tub and the bottom of the spout to pass an inspection and be safe. Since that was made, we've learned a lot about what is safe and works well.

 

Thank you so very much for your reply. I greatly appreciate it. I am so glad I found this site to post questions on. I will be lugging the ole' commode back up to my office to eternally be a decoration. It appears to be a not-so-smart idea to install it since I cannot acquire accurate plumbing for it. I am a crane operator by trade; not a plumber, so I am happy to take any advise that saves me a headache down the road.

Additionally, thank you also for the bath tub info as well... I will make sure that there is appropriate adjustments made. I have already acquired new upgraded plumbing and a faucet for it. Thank you greatly again for the reply, I truly appreciate it.