Hi there CC_JAR.
I went through this process a little while ago, so I can help you there. Delgondahntelius did have #29 but it passed on to me - [Region 1][Map 29] Mythkhardia
The process is to start like you have - find a bit which looks abandoned and ask about it. Then try to contact the original 'owner' - their name on the image Torq put up here's a link to that post - PM them and make announcment on the abadoned maps thread (link below) and/or the thread for that area ( link to the index below) which might actually give you up to date info of who's got that area now and any previous/current status about it . You'll need to wait 7 days to give time for the person working on it to reply give a shout etc, if still all quiet then it's fair game partcuarly if it's not be upated for a long time so check out the dates of the last posts.
I basically poked around a bit on all these threads to find out information. Orginally I was going to have a go on Darkone's 2 & 3 as they were inactive for months - just so happen the day I PMd him was the day before Darkone returned to continue, so I moved on to another area and Delgondahntelius was kind to let me have one of his areas (thanks again Delgondahntelius!)
Checkout the abandoned maps thread which is updated to show who's working the remaining- when possible, and this is a good link - index links of all the areas (which I keep loosing and forget where it is - the mighty Redrobes set it up in the abadoned map thread post #3 )
When you do get some turf for yourself, Redrobes can help you out there, providing you with various height field and higher resolution versions - here's what I got for #29 and if you can, it'll be great to post up regular updates on your own region's thread
The idea is to get this whole section done before moving onto another. Torq can give you more details. This is all stuff I've picked up various threads in the Cooperative Worldbuilding Project area - but it's fun and plenty of work to come when you look at the world map!
hope that helps and welcome aboard!