The Case machine does have an attachment device on the 1800 series that bolted to the CASE backhoe attachment. Because you have a Deere attachment of course you would have to fab something to make the two interface. I used this method of tying the attachment and the machine together a couple of times and than did not bother. I had no issues with not using the coupler. The 1845C mounting plates were not universal. I had issues with that on several machines. Later the pin holes and mounting plates became standardized across all machines like they are now. Like you said that is not a big deal to burn some holes. I would not get rid of the attachment, hook it up and run it and see what you think. Those attachments are heavy, you can rig additional weight off the back of the 1845C like you see guys do, max the air in the front tires helps as well.