Dont know enough about Dilly to help w that, but I am familiar w Glastrons. Post a fee pix of the boat and what year the tirle claims it is.
For a time Glastrons were made in TX, so a TX trailer under it wouldnt be surprising. If I had to quess it was sold w the boat originally, but only because the selling dealer used/sold Dillys, I wouldnt assume it came from Glastron w the boat,. But might have. A few did, like LoneStars. But LoneStar bought and re-branded a trailer from a trailer company, who escapes me this afternoon. So technically, they could be considered either an LS trailer or whoever actually made them's trailer..... Or both....
An early 60s Glastron has a serial number stamped on the aluminum L or C trim that covers the top edge of the transom. Very small stamps, 1/8in +/-, on the flat top or vertical edge, on starboard side of the motor, IIRC. If its early 60s the 3rd and 4th digits are year.
My 1960 Glastron Ser#: M160xxxx so its a 1960