The 17 parish maps in Wood's Atlas are the key to all Asylum Plans and some Tithe plans. Lots about it on Elizabeth's index on the web and Manxnotebook ditto.
I do not think anyone has scanned Lonan map from Woods, but MNH LKibrary would probably post a copy if you sent appropriate funds. Similarly if you requested individual plans but note they have little context except the holding in question.

Try posting the Asylum or Tithe plan Parish and No. and the Quarterland and owners name on here and we may be able to help.