I agree with Billm1 I use a local (Indiana) medium size shop that charges me 80-120 USD/Hour depending on difficulty of the job. There is a small shop here also for very simple jobs that charges $30/Hour
A transformer rated at 48V 300VA at nominal input will have a nominal output at 6.25A. The no load voltage you mention of 52V is about right as 300VA transformers typically have regulation (Vnoload/Vfull load) of 8 to 10%.
As the load is increased from 0 to 6.25A the output voltage will decrease...
The # E119932 is the UL file # for COPARTNER TECHNOLOGY CORP the manufacturer
AWM is Appliance Wiring Material
20276 is the type of cable
VW-1 means that it passes the UL vertical flame test
I belive the transformer you are using has an ungapped core, so each time you pulse it you increase the gauss level until it reaches saturation. To use a single ended(unipolar) pulse as an input to a transformer the transformer core must have a gap to prevent saturation or a very long off-time...