This is pretty straightforward, converting your old theme was very easy. The most important thing I did to convert was undoing your edits that you shouldn't have applied in the first place.
Let's start from scratch: you have based your custom theme on the classic theme, which is perfectly OK. However, it's a custom theme, so you should have given it a unique name (instead of just leaving the name "classic"). This will keep the theme from being overwritten when applying future updates. I have attached a zip file - unzip it into the themes folder of your coppermine install (preserving the folder structure of the zip file). Upload it and then access your coppermine-driven gallery using the "new" custom theme - go to
http://www.bookstocollect.com/gallery/?theme=hozyaliBy adding the parameter "theme=hozyali" to the address you force the use of your custom theme just for you only, while the rest of the worl would still see the theme you specified in your config (the classic theme in your case). If everything works as expected you should see your coppermine driven gallery as it used to be. Let's then go to Coppermine's config and enable the new theme for everyone who accesses your site: go to config, expand the "Themes settings" section and choose your custom theme (named "hozyali") from the "Theme" dropdown. Scroll to the bottom of the page and apply your changes.
This should give you as well as everybody else the look of your previous gallery look.
Let's then take a look at what I said above on undoing the edits you applied in error:
you have commented out some menu items that you didn't want the user to see. This is not a bright thing to do, as it just means "security by obscurity" - a user who knows his way around could still have entered the url in the address bar manually. Take a look at the upload link for example that you commented out - you better take a look at the groups page instead and disallow your users to upload in the first place if you don't want them to be capable to upload. If a user is not allowed to upload (permissions-wise) he won't see the upload link in the first place, nor will he be able to access the upload screen by entering the URL manually.
A similar thing applies to the custom link that you applied manually ("[Main Picture Gallery]"): instead of harcoding that link into your theme, just go to Coppermine's config and use "Custom menu link name" and "Custom menu link URL".
HTH
Joachim