THere are several versions of the Data East Playfield support, and it is different from the WPC games. I believe that the one that is in the TFTC, is the same as the ones that I have. There are two pivot posts on the playfield that ride on two rails, one on each side of the cabinet. These pivots allow the playfield to be tilted up, and rested on the prop rod that is inside the cabinet. If the playfield is then tilted up to vertical, there is a short ruber bungie that is bolted to the bottom of the cabinet, the hook end will be close to a eyebolt that is on the playfield, and that will hold the playfield in the full upright position. Some Data East machines have rests that can be placed on the lock bar tray, once the lock bar is removed. Lift the playfield and pull forward until the rests can set in the depression left by removing the lock bar. If you pull the playfield further forward, the back edges of the playfield will rest in the rails on the sides of the cabinet. the playfield can be pulled forward until it hits the lips on the end of these rails, and then leaned up and back against the backbox. There is no locking when it is in this position and it can come crashing down if not strapped to the head.
Hope this helps.
Mike