I did some looking, and did they make a one-piece head for the 1755? 

The reason I say this, the 1755 book calls for the 158 800 ASA head, so does the 1855. If you look at the 1850 parts book and look up a gas cylinder head, that is the 2 piece head, and it is 158 800 ASA, so I would say that the 2-piece head is right for the 1755 since it takes the same part number.

Also, the 1755 used the 283 gas engine. It used the same head as the 310 gas, but a different crank. From what I just looked up, the 1755 gas crank is the same part number as a 1655 diesel crank, go figure.

On the hydraulic cylinder, I got it 2 days after I ordered it from that Dalton Bearing and Hydraulic. It is just a little long, but it only presents a problem if you fully extend the cylinder the bucket will come back and hit the boom arm. Only time it gets that close is in transport. I went out and did some digging, and it worked just fine, and appears to be constructed very well. I did have some concern about quality since they made it themselves, but I am quite happy with it now. The point of this is I give them a thumbs up if you ever need to use them.

If I can be of any more help, just let me know.