Hi Bob,
Welcome to the forum, you'll be among friends here as there are quite a few of us who steam as well as sail
The original TSB Veronica was literally shaken to bits by the big rigs they fitted her with for racing and getting every extra knot of speed out of her
The bad news is the 1/24th scale Veronica doesn't really sail too well with the big rig, she is rather out of balance, Peter Simmonds from the Isle of Wight and a keen AMBO member has built over a dozen in the last few years, of which I have one and have raced her for the last 4 years.
Your original question really comes back to transportation as the barge even with the top mast dropped is quite awkward.
I believe the length of a 45 ft bowsprit has been mentioned which would equate to the 22 1/2"
The AMBO Facebook page gets a lot more traffic from folk building Veronica, and there is a thread on the forum called Thames Sailing Barge stuff which may help you with photos etc.
Regards Ray