Sacred Heart Tattoos is a tattoo and piercing parlour located at the end of Regent Street. The two tattoo artists I found working there were both called Dave* so I selected the Dave who recognized Tom’s picture on my smartphone.
After I explained about my project, Dave wrote authentically, with his own permanent marker pen, for me to visit his friend Lee at Blaze and provided a tattoo needle for the assemblage.
Dave informed me that he had inked Lee but that he hadn’t yet gotten around to tattooing Tom.
* A trend? The tattoo shop I visited (in  Pockets of [Reading]) also had two tattoo artists of the same name working there — both were called Adam: https://artrospektive.com/25-pockets-of-reading/pocket-number-11-the-electric-lady-reading/ .